diff --git a/packages/core/core/src/AssetGraph.js b/packages/core/core/src/AssetGraph.js
index d8c69f5e6f1..fe72be1da0b 100644
--- a/packages/core/core/src/AssetGraph.js
+++ b/packages/core/core/src/AssetGraph.js
@@ -29,6 +29,7 @@ import nullthrows from 'nullthrows';
 import {ContentGraph} from '@parcel/graph';
 import {createDependency} from './Dependency';
 import {type ProjectPath, fromProjectPathRelative} from './projectPath';
+import {DependencyFlags, EnvironmentFlags} from './types';
 
 type InitOpts = {|
   entries?: Array<ProjectPath>,
@@ -230,13 +231,14 @@ export default class AssetGraph extends ContentGraph<AssetGraphNode> {
           env: target.env,
           isEntry: true,
           needsStableName: true,
-          symbols: target.env.isLibrary
-            ? new Map([['*', {local: '*', isWeak: true, loc: null}]])
-            : undefined,
+          symbols:
+            target.env.flags & EnvironmentFlags.IS_LIBRARY
+              ? new Map([['*', {local: '*', isWeak: true, loc: null}]])
+              : undefined,
         }),
       );
 
-      if (node.value.env.isLibrary) {
+      if (node.value.env.flags & EnvironmentFlags.IS_LIBRARY) {
         // in library mode, all of the entry's symbols are "used"
         node.usedSymbolsDown.add('*');
         node.usedSymbolsUp.set('*', undefined);
@@ -401,7 +403,10 @@ export default class AssetGraph extends ContentGraph<AssetGraphNode> {
       defer = deps.every(
         d =>
           d.symbols &&
-          !(d.env.isLibrary && d.isEntry) &&
+          !(
+            d.env.flags & EnvironmentFlags.IS_LIBRARY &&
+            d.flags & DependencyFlags.ENTRY
+          ) &&
           !d.symbols.has('*') &&
           ![...d.symbols.keys()].some(symbol => {
             if (!resolvedAsset.symbols) return true;
diff --git a/packages/core/core/src/BundleGraph.js b/packages/core/core/src/BundleGraph.js
index a4a9122056c..32f03f2a69d 100644
--- a/packages/core/core/src/BundleGraph.js
+++ b/packages/core/core/src/BundleGraph.js
@@ -37,7 +37,14 @@ import {ContentGraph, ALL_EDGE_TYPES, mapVisitor} from '@parcel/graph';
 import {Hash, hashString} from '@parcel/rust';
 import {DefaultMap, objectSortedEntriesDeep, getRootDir} from '@parcel/utils';
 
-import {Priority, BundleBehavior, SpecifierType} from './types';
+import {
+  Priority,
+  BundleBehavior,
+  SpecifierType,
+  AssetFlags,
+  EnvironmentFlags,
+  EnvironmentContextNames,
+} from './types';
 import {getBundleGroupId, getPublicId} from './utils';
 import {ISOLATED_ENVS} from './public/Environment';
 import {fromProjectPath, fromProjectPathRelative} from './projectPath';
@@ -201,7 +208,7 @@ export default class BundleGraph {
       if (
         node.type === 'dependency' &&
         node.value.symbols != null &&
-        node.value.env.shouldScopeHoist &&
+        node.value.env.flags & EnvironmentFlags.SHOULD_SCOPE_HOIST &&
         // Disable in dev mode because this feature is at odds with safeToIncrementallyBundle
         isProduction
       ) {
@@ -528,7 +535,7 @@ export default class BundleGraph {
             ? BundleBehavior[opts.bundleBehavior]
             : null,
         isSplittable: opts.entryAsset
-          ? opts.entryAsset.isBundleSplittable
+          ? Boolean(opts.entryAsset.flags & AssetFlags.IS_BUNDLE_SPLITTABLE)
           : opts.isSplittable,
         isPlaceholder,
         target,
@@ -1301,7 +1308,7 @@ export default class BundleGraph {
     // If a bundle's environment is isolated, it can't access assets present
     // in any ancestor bundles. Don't consider any assets reachable.
     if (
-      ISOLATED_ENVS.has(bundle.env.context) ||
+      ISOLATED_ENVS.has(EnvironmentContextNames[bundle.env.context]) ||
       !bundle.isSplittable ||
       bundle.bundleBehavior === BundleBehavior.isolated ||
       bundle.bundleBehavior === BundleBehavior.inline
diff --git a/packages/core/core/src/CommittedAsset.js b/packages/core/core/src/CommittedAsset.js
index 9bc94e3adf4..835e8e160ae 100644
--- a/packages/core/core/src/CommittedAsset.js
+++ b/packages/core/core/src/CommittedAsset.js
@@ -8,6 +8,7 @@ import SourceMap from '@parcel/source-map';
 import {bufferStream, blobToStream, streamFromPromise} from '@parcel/utils';
 import {generateFromAST} from './assetUtils';
 import {deserializeRaw} from './serializer';
+import {AssetFlags} from './types';
 
 export default class CommittedAsset {
   value: Asset;
@@ -27,7 +28,7 @@ export default class CommittedAsset {
   getContent(): Blob | Promise<Buffer | string> {
     if (this.content == null) {
       if (this.value.contentKey != null) {
-        if (this.value.isLargeBlob) {
+        if (this.value.flags & AssetFlags.LARGE_BLOB) {
           return this.options.cache.getStream(this.value.contentKey);
         } else {
           return this.options.cache.getBlob(this.value.contentKey);
diff --git a/packages/core/core/src/Dependency.js b/packages/core/core/src/Dependency.js
index 588ccedda7d..e2882748d27 100644
--- a/packages/core/core/src/Dependency.js
+++ b/packages/core/core/src/Dependency.js
@@ -15,6 +15,7 @@ import {
   Priority,
   BundleBehavior,
   ExportsCondition,
+  DependencyFlags,
 } from './types';
 
 import {toInternalSourceLocation} from './utils';
@@ -63,20 +64,34 @@ export function createDependency(
         (opts.packageConditions ? JSON.stringify(opts.packageConditions) : ''),
     );
 
+  let {
+    placeholder,
+    promiseSymbol,
+    importAttributes,
+    isESM,
+    shouldWrap,
+    webworker,
+    ...meta
+  } = opts.meta ?? {};
+
   let dep: Dependency = {
     id,
     specifier: opts.specifier,
     specifierType: SpecifierType[opts.specifierType],
     priority: Priority[opts.priority ?? 'sync'],
-    needsStableName: opts.needsStableName ?? false,
     bundleBehavior: opts.bundleBehavior
       ? BundleBehavior[opts.bundleBehavior]
-      : null,
-    isEntry: opts.isEntry ?? false,
-    isOptional: opts.isOptional ?? false,
+      : 255,
+    flags:
+      (opts.needsStableName ? DependencyFlags.NEEDS_STABLE_NAME : 0) |
+      (opts.isEntry ? DependencyFlags.ENTRY : 0) |
+      (opts.isOptional ? DependencyFlags.OPTIONAL : 0) |
+      (isESM ? DependencyFlags.IS_ESM : 0) |
+      (shouldWrap ? DependencyFlags.SHOULD_WRAP : 0) |
+      (webworker ? DependencyFlags.IS_WEBWORKER : 0),
     loc: toInternalSourceLocation(projectRoot, opts.loc),
     env: opts.env,
-    meta: opts.meta || {},
+    meta,
     target: opts.target,
     sourceAssetId: opts.sourceAssetId,
     sourcePath: toProjectPath(projectRoot, opts.sourcePath),
@@ -98,6 +113,21 @@ export function createDependency(
     pipeline: opts.pipeline,
   };
 
+  if (typeof placeholder === 'string') {
+    dep.placeholder = placeholder;
+  }
+
+  if (typeof promiseSymbol === 'string') {
+    dep.promiseSymbol = promiseSymbol;
+  }
+
+  if (importAttributes && typeof importAttributes === 'object') {
+    dep.importAttributes = Object.entries(importAttributes).map(([k, v]) => ({
+      key: k,
+      value: (v: any),
+    }));
+  }
+
   if (opts.packageConditions) {
     convertConditions(opts.packageConditions, dep);
   }
@@ -106,7 +136,7 @@ export function createDependency(
 }
 
 export function mergeDependencies(a: Dependency, b: Dependency): void {
-  let {meta, symbols, needsStableName, isEntry, isOptional, ...other} = b;
+  let {meta, symbols, flags, ...other} = b;
   Object.assign(a, other);
   Object.assign(a.meta, meta);
   if (a.symbols && symbols) {
@@ -114,9 +144,15 @@ export function mergeDependencies(a: Dependency, b: Dependency): void {
       a.symbols.set(k, v);
     }
   }
-  if (needsStableName) a.needsStableName = true;
-  if (isEntry) a.isEntry = true;
-  if (!isOptional) a.isOptional = false;
+  if (flags & DependencyFlags.NEEDS_STABLE_NAME) {
+    a.flags |= DependencyFlags.NEEDS_STABLE_NAME;
+  }
+  if (flags & DependencyFlags.ENTRY) {
+    a.flags |= DependencyFlags.ENTRY;
+  }
+  if (!(flags & DependencyFlags.OPTIONAL)) {
+    a.flags &= ~DependencyFlags.OPTIONAL;
+  }
 }
 
 function convertConditions(conditions: Array<string>, dep: Dependency) {
diff --git a/packages/core/core/src/Environment.js b/packages/core/core/src/Environment.js
index 2c471350d60..617d9154c33 100644
--- a/packages/core/core/src/Environment.js
+++ b/packages/core/core/src/Environment.js
@@ -9,6 +9,15 @@ import {hashString} from '@parcel/rust';
 import {toInternalSourceLocation} from './utils';
 import PublicEnvironment from './public/Environment';
 import {environmentToInternalEnvironment} from './public/Environment';
+import {
+  EnvironmentContext,
+  EnvironmentContextNames,
+  EnvironmentFlags,
+  OutputFormat,
+  OutputFormatNames,
+  SourceType,
+  SourceTypeNames,
+} from './types';
 
 const DEFAULT_ENGINES = {
   browsers: ['> 0.25%'],
@@ -94,16 +103,19 @@ export function createEnvironment({
     }
   }
 
+  let flags =
+    (isLibrary ? EnvironmentFlags.IS_LIBRARY : 0) |
+    (shouldOptimize ? EnvironmentFlags.SHOULD_OPTIMIZE : 0) |
+    (shouldScopeHoist ? EnvironmentFlags.SHOULD_SCOPE_HOIST : 0);
+
   let res: Environment = {
     id: '',
-    context,
+    context: EnvironmentContext[context],
     engines,
     includeNodeModules,
-    outputFormat,
-    sourceType,
-    isLibrary,
-    shouldOptimize,
-    shouldScopeHoist,
+    outputFormat: OutputFormat[outputFormat],
+    sourceType: SourceType[sourceType],
+    flags,
     sourceMap,
     loc,
   };
@@ -129,6 +141,12 @@ export function mergeEnvironments(
   // $FlowFixMe - ignore the `id` that is already on a
   return createEnvironment({
     ...a,
+    context: EnvironmentContextNames[a.context],
+    outputFormat: OutputFormatNames[a.outputFormat],
+    sourceType: SourceTypeNames[a.sourceType],
+    isLibrary: Boolean(a.flags & EnvironmentFlags.IS_LIBRARY),
+    shouldOptimize: Boolean(a.flags & EnvironmentFlags.SHOULD_OPTIMIZE),
+    shouldScopeHoist: Boolean(a.flags & EnvironmentFlags.SHOULD_SCOPE_HOIST),
     ...b,
     loc: b.loc ? toInternalSourceLocation(projectRoot, b.loc) : a.loc,
   });
@@ -142,9 +160,7 @@ function getEnvironmentHash(env: Environment): string {
       env.includeNodeModules,
       env.outputFormat,
       env.sourceType,
-      env.isLibrary,
-      env.shouldOptimize,
-      env.shouldScopeHoist,
+      env.flags,
       env.sourceMap,
     ]),
   );
diff --git a/packages/core/core/src/PackagerRunner.js b/packages/core/core/src/PackagerRunner.js
index 7876f275c5e..ad67752a901 100644
--- a/packages/core/core/src/PackagerRunner.js
+++ b/packages/core/core/src/PackagerRunner.js
@@ -62,6 +62,7 @@ import {getInvalidationId, getInvalidationHash} from './assetUtils';
 import {optionsProxy} from './utils';
 import {invalidateDevDeps} from './requests/DevDepRequest';
 import {tracer, PluginTracer} from '@parcel/profiler';
+import {EnvironmentContext} from './types';
 
 type Opts = {|
   config: ParcelConfig,
@@ -584,7 +585,7 @@ export default class PackagerRunner {
         sourceRoot = bundle.env.sourceMap.sourceRoot;
       } else if (
         this.options.serveOptions &&
-        bundle.target.env.context === 'browser'
+        bundle.target.env.context === EnvironmentContext.browser
       ) {
         sourceRoot = '/__parcel_source_root';
       }
@@ -594,7 +595,7 @@ export default class PackagerRunner {
         bundle.env.sourceMap.inlineSources !== undefined
       ) {
         inlineSources = bundle.env.sourceMap.inlineSources;
-      } else if (bundle.target.env.context !== 'node') {
+      } else if (bundle.target.env.context !== EnvironmentContext.node) {
         // inlining should only happen in production for browser targets by default
         inlineSources = this.options.mode === 'production';
       }
diff --git a/packages/core/core/src/SymbolPropagation.js b/packages/core/core/src/SymbolPropagation.js
index 7bac77187dd..99e8c83f6fc 100644
--- a/packages/core/core/src/SymbolPropagation.js
+++ b/packages/core/core/src/SymbolPropagation.js
@@ -16,7 +16,7 @@ import nullthrows from 'nullthrows';
 import {setEqual} from '@parcel/utils';
 import logger from '@parcel/logger';
 import {md, convertSourceLocationToHighlight} from '@parcel/diagnostic';
-import {BundleBehavior} from './types';
+import {AssetFlags, BundleBehavior} from './types';
 import {fromProjectPathRelative, fromProjectPath} from './projectPath';
 
 export function propagateSymbols({
@@ -150,7 +150,7 @@ export function propagateSymbols({
         let depUsedSymbolsDown = new Set();
         dep.usedSymbolsDown = depUsedSymbolsDown;
         if (
-          assetNode.value.sideEffects ||
+          assetNode.value.flags & AssetFlags.SIDE_EFFECTS ||
           // Incoming dependency with cleared symbols
           addAll ||
           // For entries, we still need to add dep.value.symbols of the entry (which are "used" but not according to the symbols data)
@@ -408,7 +408,8 @@ export function propagateSymbols({
             let reexport = reexportedSymbols.get(s);
             let v =
               // Forward a reexport only if the current asset is side-effect free and not external
-              !assetNode.value.sideEffects && reexport != null
+              !(assetNode.value.flags & AssetFlags.SIDE_EFFECTS) &&
+              reexport != null
                 ? reexport
                 : {
                     asset: assetNode.id,
diff --git a/packages/core/core/src/Transformation.js b/packages/core/core/src/Transformation.js
index ca25f703d85..54a5746d0b1 100644
--- a/packages/core/core/src/Transformation.js
+++ b/packages/core/core/src/Transformation.js
@@ -70,6 +70,7 @@ import {
 import {invalidateOnFileCreateToInternal, createInvalidations} from './utils';
 import invariant from 'assert';
 import {tracer, PluginTracer} from '@parcel/profiler';
+import {AssetFlags} from './types';
 
 type GenerateFunc = (input: UncommittedAsset) => Promise<GenerateOutput>;
 
@@ -176,7 +177,7 @@ export default class Transformation {
 
     let pipeline = await this.loadPipeline(
       this.request.filePath,
-      asset.value.isSource,
+      Boolean(asset.value.flags & AssetFlags.IS_SOURCE),
       asset.value.pipeline,
     );
     let assets, error;
@@ -290,7 +291,7 @@ export default class Transformation {
       if (asset.value.type !== initialType) {
         nextPipeline = await this.loadNextPipeline({
           filePath: initialAsset.value.filePath,
-          isSource: asset.value.isSource,
+          isSource: Boolean(asset.value.flags & AssetFlags.IS_SOURCE),
           newType: asset.value.type,
           newPipeline: asset.value.pipeline,
           currentPipeline: pipeline,
@@ -363,7 +364,7 @@ export default class Transformation {
           asset.value.type !== initialType &&
           (await this.loadNextPipeline({
             filePath: initialAsset.value.filePath,
-            isSource: asset.value.isSource,
+            isSource: Boolean(asset.value.flags & AssetFlags.IS_SOURCE),
             newType: asset.value.type,
             newPipeline: asset.value.pipeline,
             currentPipeline: pipeline,
diff --git a/packages/core/core/src/UncommittedAsset.js b/packages/core/core/src/UncommittedAsset.js
index 6ff5b13db77..285bd6bda6f 100644
--- a/packages/core/core/src/UncommittedAsset.js
+++ b/packages/core/core/src/UncommittedAsset.js
@@ -28,7 +28,7 @@ import {createDependency, mergeDependencies} from './Dependency';
 import {mergeEnvironments} from './Environment';
 import {PARCEL_VERSION} from './constants';
 import {createAsset, createAssetIdFromOptions} from './assetUtils';
-import {BundleBehaviorNames} from './types';
+import {AssetFlags, BundleBehaviorNames} from './types';
 import {invalidateOnFileCreateToInternal, createInvalidations} from './utils';
 import {type ProjectPath, fromProjectPath} from './projectPath';
 
@@ -116,7 +116,9 @@ export default class UncommittedAsset {
       this.value.stats.size = size;
     }
 
-    this.value.isLargeBlob = this.content instanceof Readable;
+    if (this.content instanceof Readable) {
+      this.value.flags |= AssetFlags.LARGE_BLOB;
+    }
     this.value.committed = true;
   }
 
@@ -367,8 +369,9 @@ export default class UncommittedAsset {
             ? null
             : BundleBehaviorNames[this.value.bundleBehavior]),
         isBundleSplittable:
-          result.isBundleSplittable ?? this.value.isBundleSplittable,
-        isSource: this.value.isSource,
+          result.isBundleSplittable ??
+          Boolean(this.value.flags & AssetFlags.IS_BUNDLE_SPLITTABLE),
+        isSource: Boolean(this.value.flags & AssetFlags.IS_SOURCE),
         env: mergeEnvironments(
           this.options.projectRoot,
           this.value.env,
@@ -391,7 +394,9 @@ export default class UncommittedAsset {
         },
         // $FlowFixMe
         symbols: result.symbols,
-        sideEffects: result.sideEffects ?? this.value.sideEffects,
+        sideEffects:
+          result.sideEffects ??
+          Boolean(this.value.flags & AssetFlags.SIDE_EFFECTS),
         uniqueKey: result.uniqueKey,
         astGenerator: result.ast
           ? {type: result.ast.type, version: result.ast.version}
diff --git a/packages/core/core/src/assetUtils.js b/packages/core/core/src/assetUtils.js
index b55f3993704..e8c686ec308 100644
--- a/packages/core/core/src/assetUtils.js
+++ b/packages/core/core/src/assetUtils.js
@@ -37,7 +37,7 @@ import {
   fromProjectPathRelative,
 } from './projectPath';
 import {hashString} from '@parcel/rust';
-import {BundleBehavior as BundleBehaviorMap} from './types';
+import {AssetFlags, BundleBehavior as BundleBehaviorMap} from './types';
 import {PluginTracer} from '@parcel/profiler';
 
 type AssetOptions = {|
@@ -91,6 +91,15 @@ export function createAsset(
   projectRoot: FilePath,
   options: AssetOptions,
 ): Asset {
+  let {
+    shouldWrap,
+    hasCJSExports,
+    staticExports,
+    isConstantModule,
+    has_node_replacements,
+    ...meta
+  } = options.meta ?? {};
+
   return {
     id: options.id != null ? options.id : createAssetIdFromOptions(options),
     committed: options.committed ?? false,
@@ -98,19 +107,28 @@ export function createAsset(
     query: options.query,
     bundleBehavior: options.bundleBehavior
       ? BundleBehaviorMap[options.bundleBehavior]
-      : null,
-    isBundleSplittable: options.isBundleSplittable ?? true,
+      : 255,
+    flags:
+      (options.isBundleSplittable ?? true
+        ? AssetFlags.IS_BUNDLE_SPLITTABLE
+        : 0) |
+      (options.isSource ? AssetFlags.IS_SOURCE : 0) |
+      (options.sideEffects ?? true ? AssetFlags.SIDE_EFFECTS : 0) |
+      (shouldWrap === true ? AssetFlags.SHOULD_WRAP : 0) |
+      (hasCJSExports === true ? AssetFlags.HAS_CJS_EXPORTS : 0) |
+      (staticExports === true ? AssetFlags.STATIC_EXPORTS : 0) |
+      (isConstantModule === true ? AssetFlags.IS_CONSTANT_MODULE : 0) |
+      (has_node_replacements === true ? AssetFlags.HAS_NODE_REPLACEMENTS : 0),
     type: options.type,
     contentKey: options.contentKey,
     mapKey: options.mapKey,
     astKey: options.astKey,
     astGenerator: options.astGenerator,
     dependencies: options.dependencies || new Map(),
-    isSource: options.isSource,
     outputHash: options.outputHash,
     pipeline: options.pipeline,
     env: options.env,
-    meta: options.meta || {},
+    meta,
     stats: options.stats,
     symbols:
       options.symbols &&
@@ -124,7 +142,6 @@ export function createAsset(
           },
         ]),
       ),
-    sideEffects: options.sideEffects ?? true,
     uniqueKey: options.uniqueKey,
     plugin: options.plugin,
     configPath: options.configPath,
diff --git a/packages/core/core/src/dumpGraphToGraphViz.js b/packages/core/core/src/dumpGraphToGraphViz.js
index 073ad38a414..8ed389cd1b4 100644
--- a/packages/core/core/src/dumpGraphToGraphViz.js
+++ b/packages/core/core/src/dumpGraphToGraphViz.js
@@ -9,7 +9,7 @@ import {requestGraphEdgeTypes} from './RequestTracker';
 import path from 'path';
 import {fromNodeId} from '@parcel/graph';
 import {fromProjectPathRelative} from './projectPath';
-import {SpecifierType, Priority} from './types';
+import {SpecifierType, Priority, EnvironmentContextNames} from './types';
 
 const COLORS = {
   root: 'gray',
@@ -231,9 +231,13 @@ function nodeId(id) {
 function getEnvDescription(env: Environment) {
   let description;
   if (typeof env.engines.browsers === 'string') {
-    description = `${env.context}: ${env.engines.browsers}`;
+    description = `${EnvironmentContextNames[env.context]}: ${
+      env.engines.browsers
+    }`;
   } else if (Array.isArray(env.engines.browsers)) {
-    description = `${env.context}: ${env.engines.browsers.join(', ')}`;
+    description = `${
+      EnvironmentContextNames[env.context]
+    }: ${env.engines.browsers.join(', ')}`;
   } else if (env.engines.node) {
     description = `node: ${env.engines.node}`;
   } else if (env.engines.electron) {
diff --git a/packages/core/core/src/public/Asset.js b/packages/core/core/src/public/Asset.js
index 8f159925252..97d0919fa0e 100644
--- a/packages/core/core/src/public/Asset.js
+++ b/packages/core/core/src/public/Asset.js
@@ -32,6 +32,7 @@ import CommittedAsset from '../CommittedAsset';
 import {createEnvironment} from '../Environment';
 import {fromProjectPath, toProjectPath} from '../projectPath';
 import {
+  AssetFlags,
   BundleBehavior as BundleBehaviorMap,
   BundleBehaviorNames,
 } from '../types';
@@ -123,7 +124,55 @@ class BaseAsset {
   }
 
   get meta(): Meta {
-    return this.#asset.value.meta;
+    return new Proxy(this.#asset.value.meta, {
+      get: (target, prop) => {
+        let flags = this.#asset.value.flags;
+        switch (prop) {
+          case 'shouldWrap':
+            return Boolean(flags & AssetFlags.SHOULD_WRAP);
+          case 'isConstantModule':
+            return Boolean(flags & AssetFlags.IS_CONSTANT_MODULE);
+          case 'has_node_replacements':
+            return Boolean(flags & AssetFlags.HAS_NODE_REPLACEMENTS);
+          case 'hasCJSExports':
+            return Boolean(flags & AssetFlags.HAS_CJS_EXPORTS);
+          case 'staticExports':
+            return Boolean(flags & AssetFlags.STATIC_EXPORTS);
+          default:
+            return target[prop];
+        }
+      },
+      set: (target, prop, value) => {
+        let flag;
+        switch (prop) {
+          case 'shouldWrap':
+            flag = AssetFlags.SHOULD_WRAP;
+            break;
+          case 'isConstantModule':
+            flag = AssetFlags.IS_CONSTANT_MODULE;
+            break;
+          case 'has_node_replacements':
+            flag = AssetFlags.HAS_NODE_REPLACEMENTS;
+            break;
+          case 'hasCJSExports':
+            flag = AssetFlags.HAS_CJS_EXPORTS;
+            break;
+          case 'staticExports':
+            flag = AssetFlags.STATIC_EXPORTS;
+            break;
+          default:
+            target[prop] = value;
+            return true;
+        }
+
+        if (value) {
+          this.#asset.value.flags |= flag;
+        } else {
+          this.#asset.value.flags &= ~flag;
+        }
+        return true;
+      },
+    });
   }
 
   get bundleBehavior(): ?BundleBehavior {
@@ -132,15 +181,15 @@ class BaseAsset {
   }
 
   get isBundleSplittable(): boolean {
-    return this.#asset.value.isBundleSplittable;
+    return Boolean(this.#asset.value.flags & AssetFlags.IS_BUNDLE_SPLITTABLE);
   }
 
   get isSource(): boolean {
-    return this.#asset.value.isSource;
+    return Boolean(this.#asset.value.flags & AssetFlags.IS_SOURCE);
   }
 
   get sideEffects(): boolean {
-    return this.#asset.value.sideEffects;
+    return Boolean(this.#asset.value.flags & AssetFlags.SIDE_EFFECTS);
   }
 
   get symbols(): IAssetSymbols {
@@ -258,23 +307,31 @@ export class MutableAsset extends BaseAsset implements IMutableAsset {
   set bundleBehavior(bundleBehavior: ?BundleBehavior): void {
     this.#asset.value.bundleBehavior = bundleBehavior
       ? BundleBehaviorMap[bundleBehavior]
-      : null;
+      : 255;
   }
 
   get isBundleSplittable(): boolean {
-    return this.#asset.value.isBundleSplittable;
+    return Boolean(this.#asset.value.flags & AssetFlags.IS_BUNDLE_SPLITTABLE);
   }
 
   set isBundleSplittable(isBundleSplittable: boolean): void {
-    this.#asset.value.isBundleSplittable = isBundleSplittable;
+    if (isBundleSplittable) {
+      this.#asset.value.flags |= AssetFlags.IS_BUNDLE_SPLITTABLE;
+    } else {
+      this.#asset.value.flags &= ~AssetFlags.IS_BUNDLE_SPLITTABLE;
+    }
   }
 
   get sideEffects(): boolean {
-    return this.#asset.value.sideEffects;
+    return Boolean(this.#asset.value.flags & AssetFlags.SIDE_EFFECTS);
   }
 
   set sideEffects(sideEffects: boolean): void {
-    this.#asset.value.sideEffects = sideEffects;
+    if (sideEffects) {
+      this.#asset.value.flags |= AssetFlags.SIDE_EFFECTS;
+    } else {
+      this.#asset.value.flags &= ~AssetFlags.SIDE_EFFECTS;
+    }
   }
 
   get uniqueKey(): ?string {
diff --git a/packages/core/core/src/public/Dependency.js b/packages/core/core/src/public/Dependency.js
index bc060fbece2..330484d6fd6 100644
--- a/packages/core/core/src/public/Dependency.js
+++ b/packages/core/core/src/public/Dependency.js
@@ -11,7 +11,7 @@ import type {
   BundleBehavior,
 } from '@parcel/types';
 import type {Dependency as InternalDependency, ParcelOptions} from '../types';
-import {BundleBehaviorNames} from '../types';
+import {BundleBehaviorNames, DependencyFlags} from '../types';
 
 import nullthrows from 'nullthrows';
 import Environment from './Environment';
@@ -88,20 +88,20 @@ export default class Dependency implements IDependency {
   }
 
   get needsStableName(): boolean {
-    return this.#dep.needsStableName;
+    return Boolean(this.#dep.flags & DependencyFlags.NEEDS_STABLE_NAME);
   }
 
   get bundleBehavior(): ?BundleBehavior {
     let bundleBehavior = this.#dep.bundleBehavior;
-    return bundleBehavior == null ? null : BundleBehaviorNames[bundleBehavior];
+    return bundleBehavior == 255 ? null : BundleBehaviorNames[bundleBehavior];
   }
 
   get isEntry(): boolean {
-    return this.#dep.isEntry;
+    return Boolean(this.#dep.flags & DependencyFlags.ENTRY);
   }
 
   get isOptional(): boolean {
-    return this.#dep.isOptional;
+    return Boolean(this.#dep.flags & DependencyFlags.OPTIONAL);
   }
 
   get loc(): ?SourceLocation {
@@ -130,7 +130,67 @@ export default class Dependency implements IDependency {
   }
 
   get meta(): Meta {
-    return this.#dep.meta;
+    return new Proxy(this.#dep.meta, {
+      get: (target, prop) => {
+        let flags = this.#dep.flags;
+        switch (prop) {
+          case 'isESM':
+            return Boolean(flags & DependencyFlags.IS_ESM);
+          case 'shouldWrap':
+            return Boolean(flags & DependencyFlags.SHOULD_WRAP);
+          case 'webworker':
+            return Boolean(flags & DependencyFlags.IS_WEBWORKER);
+          case 'placeholder':
+            return this.#dep.placeholder;
+          case 'promiseSymbol':
+            return this.#dep.promiseSymbol;
+          case 'importAttributes':
+            if (!this.#dep.importAttributes) {
+              return {};
+            }
+            return Object.fromEntries(
+              [...this.#dep.importAttributes].map(v => [v.key, v.value]),
+            );
+          default:
+            return target[prop];
+        }
+      },
+      set: (target, prop, value) => {
+        let flag;
+        switch (prop) {
+          case 'isESM':
+            flag = DependencyFlags.IS_ESM;
+            break;
+          case 'shouldWrap':
+            flag = DependencyFlags.SHOULD_WRAP;
+            break;
+          case 'webworker':
+            flag = DependencyFlags.IS_WEBWORKER;
+            break;
+          case 'placeholder':
+            this.#dep.placeholder = value;
+            return true;
+          case 'promiseSymbol':
+            this.#dep.promiseSymbol = value;
+            return true;
+          case 'importAttributes':
+            this.#dep.importAttributes = Object.entries(value).map(
+              ([k, v]) => ({key: k, value: (v: any)}),
+            );
+            return true;
+          default:
+            target[prop] = value;
+            return true;
+        }
+
+        if (value) {
+          this.#dep.flags |= flag;
+        } else {
+          this.#dep.flags &= ~flag;
+        }
+        return true;
+      },
+    });
   }
 
   get symbols(): IMutableDependencySymbols {
diff --git a/packages/core/core/src/public/Environment.js b/packages/core/core/src/public/Environment.js
index 8123280447d..5bca97ffd12 100644
--- a/packages/core/core/src/public/Environment.js
+++ b/packages/core/core/src/public/Environment.js
@@ -16,6 +16,12 @@ import nullthrows from 'nullthrows';
 import browserslist from 'browserslist';
 import semver from 'semver';
 import {fromInternalSourceLocation} from '../utils';
+import {
+  EnvironmentContextNames,
+  EnvironmentFlags,
+  OutputFormatNames,
+  SourceTypeNames,
+} from '../types';
 
 const inspect = Symbol.for('nodejs.util.inspect.custom');
 
@@ -174,7 +180,7 @@ export default class Environment implements IEnvironment {
   }
 
   get context(): EnvironmentContext {
-    return this.#environment.context;
+    return EnvironmentContextNames[this.#environment.context];
   }
 
   get engines(): Engines {
@@ -189,23 +195,25 @@ export default class Environment implements IEnvironment {
   }
 
   get outputFormat(): OutputFormat {
-    return this.#environment.outputFormat;
+    return OutputFormatNames[this.#environment.outputFormat];
   }
 
   get sourceType(): SourceType {
-    return this.#environment.sourceType;
+    return SourceTypeNames[this.#environment.sourceType];
   }
 
   get isLibrary(): boolean {
-    return this.#environment.isLibrary;
+    return Boolean(this.#environment.flags & EnvironmentFlags.IS_LIBRARY);
   }
 
   get shouldOptimize(): boolean {
-    return this.#environment.shouldOptimize;
+    return Boolean(this.#environment.flags & EnvironmentFlags.SHOULD_OPTIMIZE);
   }
 
   get shouldScopeHoist(): boolean {
-    return this.#environment.shouldScopeHoist;
+    return Boolean(
+      this.#environment.flags & EnvironmentFlags.SHOULD_SCOPE_HOIST,
+    );
   }
 
   get sourceMap(): ?TargetSourceMapOptions {
@@ -221,31 +229,31 @@ export default class Environment implements IEnvironment {
 
   // $FlowFixMe[unsupported-syntax]
   [inspect](): string {
-    return `Env(${this.#environment.context})`;
+    return `Env(${this.context})`;
   }
 
   isBrowser(): boolean {
-    return BROWSER_ENVS.has(this.#environment.context);
+    return BROWSER_ENVS.has(this.context);
   }
 
   isNode(): boolean {
-    return NODE_ENVS.has(this.#environment.context);
+    return NODE_ENVS.has(this.context);
   }
 
   isElectron(): boolean {
-    return ELECTRON_ENVS.has(this.#environment.context);
+    return ELECTRON_ENVS.has(this.context);
   }
 
   isIsolated(): boolean {
-    return ISOLATED_ENVS.has(this.#environment.context);
+    return ISOLATED_ENVS.has(this.context);
   }
 
   isWorker(): boolean {
-    return WORKER_ENVS.has(this.#environment.context);
+    return WORKER_ENVS.has(this.context);
   }
 
   isWorklet(): boolean {
-    return this.#environment.context === 'worklet';
+    return this.context === 'worklet';
   }
 
   matchesEngines(
diff --git a/packages/core/core/src/requests/AssetGraphRequest.js b/packages/core/core/src/requests/AssetGraphRequest.js
index 9c79e87da3f..a447c009d89 100644
--- a/packages/core/core/src/requests/AssetGraphRequest.js
+++ b/packages/core/core/src/requests/AssetGraphRequest.js
@@ -23,7 +23,7 @@ import nullthrows from 'nullthrows';
 import {PromiseQueue, setEqual} from '@parcel/utils';
 import {hashString} from '@parcel/rust';
 import ThrowableDiagnostic from '@parcel/diagnostic';
-import {Priority} from '../types';
+import {DependencyFlags, Priority} from '../types';
 import AssetGraph from '../AssetGraph';
 import {PARCEL_VERSION} from '../constants';
 import createEntryRequest from './EntryRequest';
@@ -380,7 +380,11 @@ export class AssetGraphBuilder {
         } else if (!node.requested) {
           let isAsyncChild = this.assetGraph
             .getIncomingDependencies(node.value)
-            .every(dep => dep.isEntry || dep.priority !== Priority.sync);
+            .every(
+              dep =>
+                dep.flags & DependencyFlags.ENTRY ||
+                dep.priority !== Priority.sync,
+            );
           if (isAsyncChild) {
             node.requested = !isNodeLazy;
           } else {
diff --git a/packages/core/core/src/requests/TargetRequest.js b/packages/core/core/src/requests/TargetRequest.js
index 35f1171e11a..ce4fd34ac25 100644
--- a/packages/core/core/src/requests/TargetRequest.js
+++ b/packages/core/core/src/requests/TargetRequest.js
@@ -49,6 +49,7 @@ import {BROWSER_ENVS} from '../public/Environment';
 import {optionsProxy, toInternalSourceLocation} from '../utils';
 import {fromProjectPath, toProjectPath, joinProjectPath} from '../projectPath';
 import {requestTypes} from '../RequestTracker';
+import {EnvironmentContextNames, EnvironmentFlags} from '../types';
 
 type RunOpts<TResult> = {|
   input: Entry,
@@ -338,7 +339,9 @@ export class TargetResolver {
             },
           });
         }
-        if (!BROWSER_ENVS.has(targets[0].env.context)) {
+        if (
+          !BROWSER_ENVS.has(EnvironmentContextNames[targets[0].env.context])
+        ) {
           throw new ThrowableDiagnostic({
             diagnostic: {
               message: `Only browser targets are supported in serve mode`,
@@ -1606,15 +1609,15 @@ async function debugResolvedTargets(input, targets, targetInfo, options) {
       )}
              **Context**: ${target.env.context} ${format(info.context)}
              **Engines**: ${engines || ''} ${format(info.engines)}
-        **Library Mode**: ${String(target.env.isLibrary)} ${format(
-        info.isLibrary,
-      )}
+        **Library Mode**: ${String(
+          Boolean(target.env.flags & EnvironmentFlags.IS_LIBRARY),
+        )} ${format(info.isLibrary)}
 **Include Node Modules**: ${includeNodeModules} ${format(
         info.includeNodeModules,
       )}
-            **Optimize**: ${String(target.env.shouldOptimize)} ${format(
-        info.shouldOptimize,
-      )}`,
+            **Optimize**: ${String(
+              Boolean(target.env.flags & EnvironmentFlags.SHOULD_OPTIMIZE),
+            )} ${format(info.shouldOptimize)}`,
       codeFrames: target.loc
         ? [
             {
diff --git a/packages/core/core/src/types.js b/packages/core/core/src/types.js
index b355f968b09..fdb41b62c90 100644
--- a/packages/core/core/src/types.js
+++ b/packages/core/core/src/types.js
@@ -5,7 +5,6 @@ import type {
   ASTGenerator,
   BuildMode,
   Engines,
-  EnvironmentContext,
   EnvMap,
   FilePath,
   Glob,
@@ -16,12 +15,11 @@ import type {
   ReporterEvent,
   SemverRange,
   ServerOptions,
-  SourceType,
   Stats,
   Symbol,
   TargetSourceMapOptions,
   ConfigResult,
-  OutputFormat,
+  OutputFormat as TOutputFormat,
   TargetDescriptor,
   HMROptions,
   DetailedReportOptions,
@@ -63,21 +61,55 @@ export type ProcessedParcelConfig = {|
 
 export type Environment = {|
   id: string,
-  context: EnvironmentContext,
+  context: $Values<typeof EnvironmentContext>,
   engines: Engines,
   includeNodeModules:
     | boolean
     | Array<PackageName>
     | {[PackageName]: boolean, ...},
-  outputFormat: OutputFormat,
-  sourceType: SourceType,
-  isLibrary: boolean,
-  shouldOptimize: boolean,
-  shouldScopeHoist: boolean,
+  outputFormat: $Values<typeof OutputFormat>,
+  sourceType: $Values<typeof SourceType>,
+  flags: number,
   sourceMap: ?TargetSourceMapOptions,
   loc: ?InternalSourceLocation,
 |};
 
+export const EnvironmentFlags = {
+  IS_LIBRARY: 1 << 0,
+  SHOULD_OPTIMIZE: 1 << 1,
+  SHOULD_SCOPE_HOIST: 1 << 2,
+};
+
+export const OutputFormat = {
+  global: 0,
+  commonjs: 1,
+  esmodule: 2,
+};
+
+export const OutputFormatNames: Array<$Keys<typeof OutputFormat>> =
+  Object.keys(OutputFormat);
+
+export const SourceType = {
+  module: 0,
+  script: 1,
+};
+
+export const SourceTypeNames: Array<$Keys<typeof SourceType>> =
+  Object.keys(SourceType);
+
+export const EnvironmentContext = {
+  browser: 0,
+  'web-worker': 1,
+  'service-worker': 2,
+  worklet: 3,
+  node: 4,
+  'electron-main': 5,
+  'electron-renderer': 6,
+};
+
+export const EnvironmentContextNames: Array<$Keys<typeof EnvironmentContext>> =
+  Object.keys(EnvironmentContext);
+
 export type InternalSourceLocation = {|
   +filePath: ProjectPath,
   /** inclusive */
@@ -132,10 +164,10 @@ export type Dependency = {|
   specifier: DependencySpecifier,
   specifierType: $Values<typeof SpecifierType>,
   priority: $Values<typeof Priority>,
-  needsStableName: boolean,
-  bundleBehavior: ?$Values<typeof BundleBehavior>,
-  isEntry: boolean,
-  isOptional: boolean,
+  flags: number,
+  placeholder?: ?string,
+  promiseSymbol?: ?string,
+  bundleBehavior: $Values<typeof BundleBehavior>,
   loc: ?InternalSourceLocation,
   env: Environment,
   packageConditions?: number,
@@ -158,13 +190,29 @@ export type Dependency = {|
     |},
   >,
   pipeline?: ?string,
+  importAttributes?: Array<ImportAttribute>,
 |};
 
+export const DependencyFlags = {
+  ENTRY: 1 << 0,
+  OPTIONAL: 1 << 1,
+  NEEDS_STABLE_NAME: 1 << 2,
+  SHOULD_WRAP: 1 << 3,
+  IS_ESM: 1 << 4,
+  IS_WEBWORKER: 1 << 5,
+  HAS_SYMBOLS: 1 << 6,
+};
+
 export const BundleBehavior = {
   inline: 0,
   isolated: 1,
 };
 
+export type ImportAttribute = {|
+  key: string,
+  value: boolean,
+|};
+
 export const BundleBehaviorNames: Array<$Keys<typeof BundleBehavior>> =
   Object.keys(BundleBehavior);
 
@@ -175,9 +223,8 @@ export type Asset = {|
   query: ?string,
   type: string,
   dependencies: Map<string, Dependency>,
-  bundleBehavior: ?$Values<typeof BundleBehavior>,
-  isBundleSplittable: boolean,
-  isSource: boolean,
+  bundleBehavior: $Values<typeof BundleBehavior>,
+  flags: number,
   env: Environment,
   meta: Meta,
   stats: Stats,
@@ -191,14 +238,25 @@ export type Asset = {|
     Symbol,
     {|local: Symbol, loc: ?InternalSourceLocation, meta?: ?Meta|},
   >,
-  sideEffects: boolean,
   uniqueKey: ?string,
   configPath?: ProjectPath,
   plugin: ?PackageName,
   configKeyPath?: string,
-  isLargeBlob?: boolean,
 |};
 
+export const AssetFlags = {
+  IS_SOURCE: 1 << 0,
+  SIDE_EFFECTS: 1 << 1,
+  IS_BUNDLE_SPLITTABLE: 1 << 2,
+  LARGE_BLOB: 1 << 3,
+  HAS_CJS_EXPORTS: 1 << 4,
+  STATIC_EXPORTS: 1 << 5,
+  SHOULD_WRAP: 1 << 6,
+  IS_CONSTANT_MODULE: 1 << 7,
+  HAS_NODE_REPLACEMENTS: 1 << 8,
+  HAS_SYMBOLS: 1 << 9,
+};
+
 export type InternalGlob = ProjectPath;
 
 export type InternalFile = {|
@@ -315,7 +373,7 @@ export type ParcelOptions = {|
     +publicUrl: string,
     +distDir?: ProjectPath,
     +engines?: Engines,
-    +outputFormat?: OutputFormat,
+    +outputFormat?: TOutputFormat,
     +isLibrary?: boolean,
   |},
 
diff --git a/packages/core/core/test/Environment.test.js b/packages/core/core/test/Environment.test.js
index 67643f1e4e1..74b78f1d2ae 100644
--- a/packages/core/core/test/Environment.test.js
+++ b/packages/core/core/test/Environment.test.js
@@ -6,37 +6,33 @@ import {createEnvironment} from '../src/Environment';
 describe('Environment', () => {
   it('assigns a default environment with nothing passed', () => {
     assert.deepEqual(createEnvironment(), {
-      id: 'c242f987e3544367',
-      context: 'browser',
+      id: '788187fcd358de46',
+      context: 0,
       engines: {
         browsers: ['> 0.25%'],
       },
       includeNodeModules: true,
-      outputFormat: 'global',
-      isLibrary: false,
-      shouldOptimize: false,
-      shouldScopeHoist: false,
+      outputFormat: 0,
+      flags: 0,
       sourceMap: undefined,
       loc: undefined,
-      sourceType: 'module',
+      sourceType: 0,
     });
   });
 
   it('assigns a node context if a node engine is given', () => {
     assert.deepEqual(createEnvironment({engines: {node: '>= 10.0.0'}}), {
-      id: '69e0ab7220ee8f7a',
-      context: 'node',
+      id: '2f10f79854f6b94b',
+      context: 4,
       engines: {
         node: '>= 10.0.0',
       },
       includeNodeModules: false,
-      outputFormat: 'commonjs',
-      isLibrary: false,
-      shouldOptimize: false,
-      shouldScopeHoist: false,
+      outputFormat: 1,
+      flags: 0,
       sourceMap: undefined,
       loc: undefined,
-      sourceType: 'module',
+      sourceType: 0,
     });
   });
 
@@ -44,56 +40,50 @@ describe('Environment', () => {
     assert.deepEqual(
       createEnvironment({engines: {browsers: ['last 1 version']}}),
       {
-        id: '4b5c9005af8c5b19',
-        context: 'browser',
+        id: '314954654e82feb3',
+        context: 0,
         engines: {
           browsers: ['last 1 version'],
         },
         includeNodeModules: true,
-        outputFormat: 'global',
-        isLibrary: false,
-        shouldOptimize: false,
-        shouldScopeHoist: false,
+        outputFormat: 0,
+        flags: 0,
         sourceMap: undefined,
         loc: undefined,
-        sourceType: 'module',
+        sourceType: 0,
       },
     );
   });
 
   it('assigns default engines for node', () => {
     assert.deepEqual(createEnvironment({context: 'node'}), {
-      id: 'f7c9644283a8698f',
-      context: 'node',
+      id: '81b1dde8607da1b5',
+      context: 4,
       engines: {
         node: '>= 8.0.0',
       },
       includeNodeModules: false,
-      outputFormat: 'commonjs',
-      isLibrary: false,
-      shouldOptimize: false,
-      shouldScopeHoist: false,
+      outputFormat: 1,
+      flags: 0,
       sourceMap: undefined,
       loc: undefined,
-      sourceType: 'module',
+      sourceType: 0,
     });
   });
 
   it('assigns default engines for browsers', () => {
     assert.deepEqual(createEnvironment({context: 'browser'}), {
-      id: 'c242f987e3544367',
-      context: 'browser',
+      id: '788187fcd358de46',
+      context: 0,
       engines: {
         browsers: ['> 0.25%'],
       },
       includeNodeModules: true,
-      outputFormat: 'global',
-      isLibrary: false,
-      shouldOptimize: false,
-      shouldScopeHoist: false,
+      outputFormat: 0,
+      flags: 0,
       sourceMap: undefined,
       loc: undefined,
-      sourceType: 'module',
+      sourceType: 0,
     });
   });
 });
diff --git a/packages/core/core/test/TargetRequest.test.js b/packages/core/core/test/TargetRequest.test.js
index caeb37b1db7..1e02b4eee3d 100644
--- a/packages/core/core/test/TargetRequest.test.js
+++ b/packages/core/core/test/TargetRequest.test.js
@@ -125,19 +125,17 @@ describe('TargetResolver', () => {
           publicUrl: '/',
           distDir: normalizeSeparators(path.resolve('customA')),
           env: {
-            id: '1d40417b63734b32',
-            context: 'browser',
+            id: 'ebeaeb5c680f8c4f',
+            context: 0,
             includeNodeModules: true,
             engines: {
               browsers: ['> 0.25%'],
             },
-            outputFormat: 'global',
-            isLibrary: false,
-            shouldOptimize: false,
-            shouldScopeHoist: false,
+            outputFormat: 0,
+            flags: 0,
             sourceMap: {},
             loc: undefined,
-            sourceType: 'module',
+            sourceType: 0,
           },
         },
         {
@@ -146,19 +144,17 @@ describe('TargetResolver', () => {
           distEntry: 'b.js',
           distDir: normalizeSeparators(path.resolve('customB')),
           env: {
-            id: '928f0d1c941b2e57',
-            context: 'node',
+            id: 'f4bd25724ba4f641',
+            context: 4,
             includeNodeModules: false,
             engines: {
               node: '>= 8.0.0',
             },
-            outputFormat: 'commonjs',
-            isLibrary: false,
-            shouldOptimize: false,
-            shouldScopeHoist: false,
+            outputFormat: 1,
+            flags: 0,
             sourceMap: {},
             loc: undefined,
-            sourceType: 'module',
+            sourceType: 0,
           },
         },
       ],
@@ -177,19 +173,17 @@ describe('TargetResolver', () => {
           distEntry: 'index.js',
           publicUrl: '/',
           env: {
-            id: 'b552bd32da37fa8b',
-            context: 'node',
+            id: '8da8f90dd22edc64',
+            context: 4,
             engines: {
               node: '>= 8.0.0',
             },
             includeNodeModules: false,
-            outputFormat: 'commonjs',
-            isLibrary: true,
-            shouldOptimize: false,
-            shouldScopeHoist: true,
+            outputFormat: 1,
+            flags: 5,
             sourceMap: {},
             loc: undefined,
-            sourceType: 'module',
+            sourceType: 0,
           },
           loc: {
             filePath: relative(
@@ -211,21 +205,19 @@ describe('TargetResolver', () => {
           distEntry: 'index.js',
           publicUrl: '/',
           env: {
-            id: '8804e4eb97e2703e',
-            context: 'browser',
+            id: 'd062445afb902bbd',
+            context: 0,
             engines: {
               browsers: ['last 1 version'],
             },
             includeNodeModules: false,
-            outputFormat: 'esmodule',
-            isLibrary: true,
-            shouldOptimize: false,
-            shouldScopeHoist: true,
+            outputFormat: 2,
+            flags: 5,
             sourceMap: {
               inlineSources: true,
             },
             loc: undefined,
-            sourceType: 'module',
+            sourceType: 0,
           },
           loc: {
             filePath: relative(
@@ -247,19 +239,17 @@ describe('TargetResolver', () => {
           distEntry: 'index.js',
           publicUrl: '/assets',
           env: {
-            id: 'a7ed3e73c53f1923',
-            context: 'browser',
+            id: '4dea6f5d061ef847',
+            context: 0,
             engines: {
               browsers: ['last 1 version'],
             },
             includeNodeModules: false,
-            outputFormat: 'commonjs',
-            isLibrary: true,
-            shouldOptimize: false,
-            shouldScopeHoist: true,
+            outputFormat: 1,
+            flags: 5,
             sourceMap: {},
             loc: undefined,
-            sourceType: 'module',
+            sourceType: 0,
           },
           loc: {
             filePath: relative(
@@ -293,19 +283,17 @@ describe('TargetResolver', () => {
           distEntry: 'index.js',
           publicUrl: '/',
           env: {
-            id: 'f7c9644283a8698f',
-            context: 'node',
+            id: '81b1dde8607da1b5',
+            context: 4,
             engines: {
               node: '>= 8.0.0',
             },
             includeNodeModules: false,
-            outputFormat: 'commonjs',
-            isLibrary: false,
-            shouldOptimize: false,
-            shouldScopeHoist: false,
+            outputFormat: 1,
+            flags: 0,
             sourceMap: undefined,
             loc: undefined,
-            sourceType: 'module',
+            sourceType: 0,
           },
           loc: {
             filePath: relative(
@@ -336,19 +324,17 @@ describe('TargetResolver', () => {
           distEntry: 'index.js',
           publicUrl: '/',
           env: {
-            id: 'b552bd32da37fa8b',
-            context: 'node',
+            id: '8da8f90dd22edc64',
+            context: 4,
             engines: {
               node: '>= 8.0.0',
             },
             includeNodeModules: false,
-            outputFormat: 'commonjs',
-            isLibrary: true,
-            shouldOptimize: false,
-            shouldScopeHoist: true,
+            outputFormat: 1,
+            flags: 5,
             sourceMap: {},
             loc: undefined,
-            sourceType: 'module',
+            sourceType: 0,
           },
           loc: {
             filePath: relative(
@@ -370,19 +356,17 @@ describe('TargetResolver', () => {
           distEntry: 'index.js',
           publicUrl: '/',
           env: {
-            id: '1f28e9ceaf633d83',
-            context: 'browser',
+            id: 'e9da10cde4f3ea10',
+            context: 0,
             engines: {
               browsers: ['last 1 version'],
             },
             includeNodeModules: true,
-            outputFormat: 'global',
-            isLibrary: false,
-            shouldOptimize: false,
-            shouldScopeHoist: false,
+            outputFormat: 0,
+            flags: 0,
             sourceMap: {},
             loc: undefined,
-            sourceType: 'module',
+            sourceType: 0,
           },
           loc: {
             filePath: relative(
@@ -404,19 +388,17 @@ describe('TargetResolver', () => {
           distEntry: 'index.js',
           publicUrl: '/',
           env: {
-            id: '767bf6e6b675c4f3',
-            context: 'browser',
+            id: 'dc8614216bb832dc',
+            context: 0,
             engines: {
               browsers: ['ie11'],
             },
             includeNodeModules: true,
-            outputFormat: 'global',
-            isLibrary: false,
-            shouldOptimize: false,
-            shouldScopeHoist: false,
+            outputFormat: 0,
+            flags: 0,
             sourceMap: {},
             loc: undefined,
-            sourceType: 'module',
+            sourceType: 0,
           },
           loc: {
             filePath: relative(
@@ -455,19 +437,17 @@ describe('TargetResolver', () => {
           distEntry: 'index.js',
           publicUrl: '/',
           env: {
-            id: 'b552bd32da37fa8b',
-            context: 'node',
+            id: '8da8f90dd22edc64',
+            context: 4,
             engines: {
               node: '>= 8.0.0',
             },
             includeNodeModules: false,
-            outputFormat: 'commonjs',
-            isLibrary: true,
-            shouldOptimize: false,
-            shouldScopeHoist: true,
+            outputFormat: 1,
+            flags: 5,
             sourceMap: {},
             loc: undefined,
-            sourceType: 'module',
+            sourceType: 0,
           },
           loc: {
             filePath: relative(
@@ -489,19 +469,17 @@ describe('TargetResolver', () => {
           distEntry: 'index.js',
           publicUrl: '/',
           env: {
-            id: 'ed7c0e65adee71c9',
-            context: 'browser',
+            id: 'efbc33e1298d8d31',
+            context: 0,
             engines: {
               browsers: ['last 1 version'],
             },
             includeNodeModules: true,
-            outputFormat: 'global',
-            isLibrary: false,
-            shouldOptimize: true,
-            shouldScopeHoist: false,
+            outputFormat: 0,
+            flags: 2,
             sourceMap: {},
             loc: undefined,
-            sourceType: 'module',
+            sourceType: 0,
           },
           loc: {
             filePath: relative(
@@ -523,19 +501,17 @@ describe('TargetResolver', () => {
           distEntry: 'index.js',
           publicUrl: '/',
           env: {
-            id: 'f7692543e59e4c0a',
-            context: 'browser',
+            id: '2713f02ea149891e',
+            context: 0,
             engines: {
               browsers: ['ie11'],
             },
             includeNodeModules: true,
-            outputFormat: 'global',
-            isLibrary: false,
-            shouldOptimize: true,
-            shouldScopeHoist: false,
+            outputFormat: 0,
+            flags: 2,
             sourceMap: {},
             loc: undefined,
-            sourceType: 'module',
+            sourceType: 0,
           },
           loc: {
             filePath: relative(
@@ -566,19 +542,17 @@ describe('TargetResolver', () => {
           distEntry: undefined,
           publicUrl: 'www',
           env: {
-            id: 'ddb6ac7c9a3a9178',
-            context: 'browser',
+            id: 'f674466050f0db8f',
+            context: 0,
             engines: {
               browsers: '> 0.25%',
             },
             includeNodeModules: true,
-            outputFormat: 'global',
-            isLibrary: false,
-            shouldOptimize: false,
-            shouldScopeHoist: false,
+            outputFormat: 0,
+            flags: 0,
             sourceMap: {},
             loc: undefined,
-            sourceType: 'module',
+            sourceType: 0,
           },
           loc: {
             filePath: relative(
@@ -621,19 +595,17 @@ describe('TargetResolver', () => {
           distDir: normalizeSeparators(path.resolve('customB')),
           publicUrl: '/',
           env: {
-            id: '1d40417b63734b32',
-            context: 'browser',
+            id: 'ebeaeb5c680f8c4f',
+            context: 0,
             engines: {
               browsers: ['> 0.25%'],
             },
             includeNodeModules: true,
-            outputFormat: 'global',
-            isLibrary: false,
-            shouldOptimize: false,
-            shouldScopeHoist: false,
+            outputFormat: 0,
+            flags: 0,
             sourceMap: {},
             loc: undefined,
-            sourceType: 'module',
+            sourceType: 0,
           },
         },
       ],
@@ -663,19 +635,17 @@ describe('TargetResolver', () => {
           distDir: normalizeSeparators(path.resolve('customA')),
           publicUrl: '/',
           env: {
-            id: '1d40417b63734b32',
-            context: 'browser',
+            id: 'ebeaeb5c680f8c4f',
+            context: 0,
             engines: {
               browsers: ['> 0.25%'],
             },
             includeNodeModules: true,
-            outputFormat: 'global',
-            isLibrary: false,
-            shouldOptimize: false,
-            shouldScopeHoist: false,
+            outputFormat: 0,
+            flags: 0,
             sourceMap: {},
             loc: undefined,
-            sourceType: 'module',
+            sourceType: 0,
           },
           source: 'customA/index.js',
         },
@@ -692,8 +662,8 @@ describe('TargetResolver', () => {
         distEntry: 'index.js',
         publicUrl: '/',
         env: {
-          id: '6aafdb9eaa4a3812',
-          context: 'node',
+          id: '73ec4b016d461abc',
+          context: 4,
           engines: {
             browsers: [
               'last 1 Chrome version',
@@ -703,13 +673,11 @@ describe('TargetResolver', () => {
             ],
           },
           includeNodeModules: false,
-          isLibrary: true,
-          outputFormat: 'commonjs',
-          shouldOptimize: false,
-          shouldScopeHoist: true,
+          outputFormat: 1,
+          flags: 5,
           sourceMap: {},
           loc: undefined,
-          sourceType: 'module',
+          sourceType: 0,
         },
         loc: {
           filePath: relative(path.join(CONTEXT_FIXTURE_PATH, 'package.json')),
@@ -1070,8 +1038,8 @@ describe('TargetResolver', () => {
         distEntry: 'index.mjs',
         publicUrl: '/',
         env: {
-          id: '439701173a9199ea',
-          context: 'browser',
+          id: 'a30b733cec75c314',
+          context: 0,
           engines: {
             browsers: [
               'last 1 Chrome version',
@@ -1081,13 +1049,11 @@ describe('TargetResolver', () => {
             ],
           },
           includeNodeModules: true,
-          outputFormat: 'esmodule',
-          isLibrary: false,
-          shouldOptimize: false,
-          shouldScopeHoist: false,
+          outputFormat: 2,
+          flags: 0,
           sourceMap: {},
           loc: undefined,
-          sourceType: 'module',
+          sourceType: 0,
         },
         loc: {
           filePath: relative(path.join(fixture, 'package.json')),
@@ -1115,8 +1081,8 @@ describe('TargetResolver', () => {
         distEntry: 'index.js',
         publicUrl: '/',
         env: {
-          id: '439701173a9199ea',
-          context: 'browser',
+          id: 'a30b733cec75c314',
+          context: 0,
           engines: {
             browsers: [
               'last 1 Chrome version',
@@ -1126,13 +1092,11 @@ describe('TargetResolver', () => {
             ],
           },
           includeNodeModules: true,
-          outputFormat: 'esmodule',
-          isLibrary: false,
-          shouldOptimize: false,
-          shouldScopeHoist: false,
+          outputFormat: 2,
+          flags: 0,
           sourceMap: {},
           loc: undefined,
-          sourceType: 'module',
+          sourceType: 0,
         },
         loc: {
           filePath: relative(path.join(fixture, 'package.json')),
@@ -1164,19 +1128,17 @@ describe('TargetResolver', () => {
           distEntry: 'index.js',
           publicUrl: '/',
           env: {
-            id: 'b552bd32da37fa8b',
-            context: 'node',
+            id: '8da8f90dd22edc64',
+            context: 4,
             engines: {
               node: '>= 8.0.0',
             },
             includeNodeModules: false,
-            outputFormat: 'commonjs',
-            isLibrary: true,
-            shouldOptimize: false,
-            shouldScopeHoist: true,
+            outputFormat: 1,
+            flags: 5,
             sourceMap: {},
             loc: undefined,
-            sourceType: 'module',
+            sourceType: 0,
           },
           loc: {
             filePath: relative(
@@ -1198,19 +1160,17 @@ describe('TargetResolver', () => {
           distEntry: 'index.js',
           publicUrl: '/assets',
           env: {
-            id: 'a7ed3e73c53f1923',
-            context: 'browser',
+            id: '4dea6f5d061ef847',
+            context: 0,
             engines: {
               browsers: ['last 1 version'],
             },
             includeNodeModules: false,
-            outputFormat: 'commonjs',
-            isLibrary: true,
-            shouldOptimize: false,
-            shouldScopeHoist: true,
+            outputFormat: 1,
+            flags: 5,
             sourceMap: {},
             loc: undefined,
-            sourceType: 'module',
+            sourceType: 0,
           },
           loc: {
             filePath: relative(
@@ -1246,8 +1206,8 @@ describe('TargetResolver', () => {
           distDir: '.parcel-cache/dist',
           publicUrl: '/',
           env: {
-            id: 'd6ea1d42532a7575',
-            context: 'browser',
+            id: '00d1d0d64778b6f2',
+            context: 0,
             engines: {
               browsers: [
                 'last 1 Chrome version',
@@ -1257,13 +1217,11 @@ describe('TargetResolver', () => {
               ],
             },
             includeNodeModules: true,
-            outputFormat: 'global',
-            isLibrary: false,
-            shouldOptimize: false,
-            shouldScopeHoist: false,
+            outputFormat: 0,
+            flags: 0,
             sourceMap: {},
             loc: undefined,
-            sourceType: 'module',
+            sourceType: 0,
           },
         },
       ],
@@ -1283,19 +1241,17 @@ describe('TargetResolver', () => {
           ),
           publicUrl: '/',
           env: {
-            id: 'a9c07d094d038c73',
-            context: 'browser',
+            id: 'de832a9db5707a5a',
+            context: 0,
             engines: {
               browsers: ['Chrome 80'],
             },
             includeNodeModules: true,
-            outputFormat: 'global',
-            isLibrary: false,
-            shouldOptimize: false,
-            shouldScopeHoist: false,
+            outputFormat: 0,
+            flags: 0,
             sourceMap: {},
             loc: undefined,
-            sourceType: 'module',
+            sourceType: 0,
           },
         },
       ],
@@ -1316,19 +1272,17 @@ describe('TargetResolver', () => {
           distEntry: undefined,
           publicUrl: '/',
           env: {
-            id: 'a9c07d094d038c73',
-            context: 'browser',
+            id: 'de832a9db5707a5a',
+            context: 0,
             engines: {
               browsers: ['Chrome 80'],
             },
             includeNodeModules: true,
-            outputFormat: 'global',
-            isLibrary: false,
-            shouldOptimize: false,
-            shouldScopeHoist: false,
+            outputFormat: 0,
+            flags: 0,
             sourceMap: {},
             loc: undefined,
-            sourceType: 'module',
+            sourceType: 0,
           },
           loc: {
             filePath: relative(
@@ -1366,19 +1320,17 @@ describe('TargetResolver', () => {
           distEntry: undefined,
           publicUrl: '/',
           env: {
-            id: '1f28e9ceaf633d83',
-            context: 'browser',
+            id: 'e9da10cde4f3ea10',
+            context: 0,
             engines: {
               browsers: ['last 1 version'],
             },
             includeNodeModules: true,
-            outputFormat: 'global',
-            isLibrary: false,
-            shouldOptimize: false,
-            shouldScopeHoist: false,
+            outputFormat: 0,
+            flags: 0,
             sourceMap: {},
             loc: undefined,
-            sourceType: 'module',
+            sourceType: 0,
           },
           loc: {
             filePath: relative(
@@ -1406,19 +1358,17 @@ describe('TargetResolver', () => {
           distEntry: undefined,
           publicUrl: '/',
           env: {
-            id: '824e113c03cab3c8',
-            context: 'browser',
+            id: 'c8a9da03abcc3247',
+            context: 0,
             engines: {
               browsers: ['IE 11'],
             },
             includeNodeModules: true,
-            outputFormat: 'global',
-            isLibrary: false,
-            shouldOptimize: false,
-            shouldScopeHoist: false,
+            outputFormat: 0,
+            flags: 0,
             sourceMap: {},
             loc: undefined,
-            sourceType: 'module',
+            sourceType: 0,
           },
           loc: {
             filePath: relative(
diff --git a/packages/core/integration-tests/test/bundler.js b/packages/core/integration-tests/test/bundler.js
index c72d44b2f3f..fda98450dad 100644
--- a/packages/core/integration-tests/test/bundler.js
+++ b/packages/core/integration-tests/test/bundler.js
@@ -1756,13 +1756,13 @@ describe('bundler', function () {
           assets: ['index.html'],
         },
         {
-          assets: ['a.js', 'i.js'],
+          assets: ['a.js', 'b.js', 'd.js', 'h.js', 'i.js'],
         },
         {
-          assets: ['vendor.js', 'b.js', 'j.js'],
+          assets: ['j.js'],
         },
         {
-          assets: ['c.js', 'd.js', 'e.js', 'f.js', 'g.js', 'h.js'],
+          assets: ['c.js', 'e.js', 'f.js', 'g.js', 'vendor.js'],
         },
         {
           assets: ['esmodule-helpers.js', 'index.js'],
diff --git a/packages/core/integration-tests/test/javascript.js b/packages/core/integration-tests/test/javascript.js
index e1d9c7839f8..c68632a5593 100644
--- a/packages/core/integration-tests/test/javascript.js
+++ b/packages/core/integration-tests/test/javascript.js
@@ -4667,7 +4667,7 @@ describe('javascript', function () {
       b.getBundles().find(b => b.type === 'js').filePath,
       'utf8',
     );
-    assert(dist.includes('$cPUKg$lodash = require("lodash");'));
+    assert(dist.includes('$4tAd3$lodash = require("lodash");'));
 
     let add = await run(b);
     assert.equal(add(2, 3), 5);
@@ -4687,7 +4687,7 @@ describe('javascript', function () {
 
     assert(
       dist.includes(
-        'const add = require(`lodash/${$8cad8166811e0063$var$fn}`);',
+        'const add = require(`lodash/${$b4fd1a594eed7898$var$fn}`);',
       ),
     );
 
diff --git a/packages/core/integration-tests/test/sourcemaps.js b/packages/core/integration-tests/test/sourcemaps.js
index 39040fd4a4e..571c9ca6a88 100644
--- a/packages/core/integration-tests/test/sourcemaps.js
+++ b/packages/core/integration-tests/test/sourcemaps.js
@@ -448,7 +448,7 @@ describe('sourcemaps', function () {
       source: inputs[0],
       generated: raw,
       str: 'const local',
-      generatedStr: 'let o',
+      generatedStr: 'let t',
       sourcePath: 'index.js',
     });
 
@@ -457,7 +457,7 @@ describe('sourcemaps', function () {
       source: inputs[0],
       generated: raw,
       str: 'local.a',
-      generatedStr: 'o.a',
+      generatedStr: 't.a',
       sourcePath: 'index.js',
     });
 
@@ -466,7 +466,7 @@ describe('sourcemaps', function () {
       source: inputs[1],
       generated: raw,
       str: 'exports.a',
-      generatedStr: 't.a',
+      generatedStr: 'o.a',
       sourcePath: 'local.js',
     });
 
@@ -475,7 +475,7 @@ describe('sourcemaps', function () {
       source: inputs[2],
       generated: raw,
       str: 'exports.count = function(a, b) {',
-      generatedStr: 't.count=function(e,n){',
+      generatedStr: 'o.count=function(e,n){',
       sourcePath: 'utils/util.js',
     });
   });