diff --git a/build/add-js-extensions.mjs b/build/add-js-extensions.mjs
deleted file mode 100644
index bbaf8d99f1..0000000000
--- a/build/add-js-extensions.mjs
+++ /dev/null
@@ -1,97 +0,0 @@
-#!/usr/bin/env node
-// Script to add .js extensions to all relative imports in TypeScript files
-// This is required for ESM compatibility
-
-import { promises as fs } from 'fs';
-import path from 'path';
-import { fileURLToPath } from 'url';
-
-const __filename = fileURLToPath(import.meta.url);
-const __dirname = path.dirname(__filename);
-
-const rootDir = path.join(__dirname, '..');
-const srcDir = path.join(rootDir, 'src');
-
-// Regex patterns to match import statements with relative paths
-// Updated to handle multi-line imports/exports by using [\s\S] to match newlines
-const importPatterns = [
-    // import ... from './path' or '../path' (supports multi-line named imports)
-    /^(\s*import\s+[\s\S]+?from\s+['"])(\.\/.+?|\.\.?\/.+?)(['"])/gm,
-    // export ... from './path' or '../path' (supports multi-line named exports)
-    /^(\s*export\s+[\s\S]+?from\s+['"])(\.\/.+?|\.\.?\/.+?)(['"])/gm,
-    // import('./path') or import('../path') (supports newlines before parentheses and quotes)
-    /(\bimport[\s\S]*?\([\s\S]*?['"])(\.\/.+?|\.\.?\/.+?)(['"])/gm,
-    // await import('./path') (supports newlines in await import statements)
-    /(\bawait\s+import[\s\S]*?\([\s\S]*?['"])(\.\/.+?|\.\.?\/.+?)(['"])/gm,
-];
-
-async function getAllTsFiles(dir) {
-    const files = [];
-    const entries = await fs.readdir(dir, { withFileTypes: true });
-
-    for (const entry of entries) {
-        const fullPath = path.join(dir, entry.name);
-
-        if (entry.isDirectory()) {
-            // Skip node_modules, out, dist, etc.
-            if (!['node_modules', 'out', 'dist', '.git', '.vscode', 'resources'].includes(entry.name)) {
-                files.push(...(await getAllTsFiles(fullPath)));
-            }
-        } else if ((entry.name.endsWith('.ts') || entry.name.endsWith('.tsx')) && !entry.name.endsWith('.d.ts')) {
-            // Include .ts and .tsx files, but exclude .d.ts declaration files
-            files.push(fullPath);
-        }
-    }
-
-    return files;
-}
-
-function addJsExtension(content) {
-    let modified = content;
-    let changeCount = 0;
-
-    for (const pattern of importPatterns) {
-        modified = modified.replace(pattern, (match, before, importPath, after) => {
-            // Skip if already has an extension
-            if (/\.(js|ts|tsx|json|css|less|svg|png|jpg)$/i.test(importPath)) {
-                return match;
-            }
-
-            changeCount++;
-            return `${before}${importPath}.js${after}`;
-        });
-    }
-
-    return { content: modified, changed: changeCount > 0, changeCount };
-}
-
-async function main() {
-    console.log('🔍 Finding all TypeScript files in src/...');
-    const tsFiles = await getAllTsFiles(srcDir);
-    console.log(`📁 Found ${tsFiles.length} TypeScript files\n`);
-
-    let totalFilesChanged = 0;
-    let totalImportsChanged = 0;
-
-    for (const file of tsFiles) {
-        const content = await fs.readFile(file, 'utf-8');
-        const { content: newContent, changed, changeCount } = addJsExtension(content);
-
-        if (changed) {
-            await fs.writeFile(file, newContent, 'utf-8');
-            totalFilesChanged++;
-            totalImportsChanged += changeCount;
-            const relativePath = path.relative(rootDir, file);
-            console.log(`✅ ${relativePath} (${changeCount} import${changeCount > 1 ? 's' : ''})`);
-        }
-    }
-
-    console.log(`\n✨ Done!`);
-    console.log(`📊 Modified ${totalFilesChanged} files`);
-    console.log(`🔗 Updated ${totalImportsChanged} import statements`);
-}
-
-main().catch(error => {
-    console.error('❌ Error:', error);
-    process.exit(1);
-});
diff --git a/build/esbuild/build.ts b/build/esbuild/build.ts
index 5761205363..06edf8765c 100644
--- a/build/esbuild/build.ts
+++ b/build/esbuild/build.ts
@@ -43,25 +43,27 @@ const deskTopNodeModulesToExternalize = [
     // Lazy loaded modules.
     'vscode-languageclient/node',
     '@jupyterlab/nbformat',
-    'vscode-jsonrpc'
+    'vscode-jsonrpc',
+    // vega-lite uses top-level await (through vega-canvas), must be external
+    'vega-lite'
 ];
 const commonExternals = [
     'log4js',
     'vscode',
     'commonjs',
-    'module', // Node.js builtin module for createRequire (ESM support)
-    'node:os', // Node.js builtin (use node: prefix for ESM)
-    'ansi-regex', // Used by regexp utils
-    'node:crypto',
-    'node:fs/promises',
-    'node:path',
     'vscode-jsonrpc', // Used by a few modules, might as well pull this out, instead of duplicating it in separate bundles.
     // Ignore telemetry specific packages that are not required.
     'applicationinsights-native-metrics',
     '@opentelemetry/tracing',
     '@azure/opentelemetry-instrumentation-azure-sdk',
     '@opentelemetry/instrumentation',
-    '@azure/functions-core'
+    '@azure/functions-core',
+    // Node.js builtins (with node: prefix)
+    'node:crypto',
+    'node:fs/promises',
+    'node:os',
+    'node:path',
+    'ansi-regex' // Used by regexp utils
 ];
 // Create separate copies to avoid shared-state mutations
 const webExternals = [...commonExternals];
@@ -237,20 +239,23 @@ function createConfig(
     }
     const isPreRelease = isDevbuild || process.env.IS_PRE_RELEASE_VERSION_OF_JUPYTER_EXTENSION === 'true';
     const releaseVersionScriptFile = isPreRelease ? 'release.pre-release.js' : 'release.stable.js';
-    const alias = {
+    const alias: Record<string, string> = {
         moment: path.join(extensionFolder, 'build', 'webpack', 'moment.js'),
         'vscode-jupyter-release-version': path.join(__dirname, releaseVersionScriptFile)
     };
+    // Use ESM entry for jsonc-parser to avoid UMD internal require() issues when bundling
     if (target === 'desktop') {
         alias['jsonc-parser'] = path.join(extensionFolder, 'node_modules', 'jsonc-parser', 'lib', 'esm', 'main.js');
     }
+    // Desktop builds use CommonJS for VS Code/Cursor compatibility
+    // Web builds use ESM for browser compatibility
     const config: SameShape<BuildOptions, BuildOptions> = {
         entryPoints: [source],
         outfile,
         bundle: true,
         external,
         alias,
-        format: 'esm',
+        format: target === 'desktop' ? 'cjs' : 'esm',
         metafile: isDevbuild && !watch,
         define,
         target: target === 'desktop' ? 'node18' : 'es2018',
@@ -263,18 +268,6 @@ function createConfig(
         loader: target === 'desktop' ? {} : loader
     };
 
-    // Add createRequire banner for desktop ESM builds to support external CommonJS modules
-    if (target === 'desktop') {
-        config.banner = {
-            js: `import { createRequire as __createRequire } from 'module';
-import { fileURLToPath as __fileURLToPath } from 'url';
-import { dirname as __getDirname } from 'path';
-const require = __createRequire(import.meta.url);
-const __filename = __fileURLToPath(import.meta.url);
-const __dirname = __getDirname(__filename);`
-        };
-    }
-
     return config;
 }
 async function build(source: string, outfile: string, options: { watch: boolean; target: 'desktop' | 'web' }) {
@@ -451,18 +444,10 @@ async function buildAll() {
                 { target: 'desktop', watch: isWatchMode }
             )
         );
-        builders.push(
-            build(
-                path.join(extensionFolder, 'src', 'extension.node.proxy.ts'),
-                path.join(extensionFolder, 'dist', 'extension.node.proxy.js'),
-                // This file almost never ever changes, hence no need to watch this.
-                { target: 'desktop', watch: false }
-            )
-        );
         builders.push(
             ...deskTopNodeModulesToExternalize
-                // zeromq will be manually bundled.
-                .filter((module) => !['zeromq', 'zeromqold', 'vscode-jsonrpc'].includes(module))
+                // zeromq will be manually bundled, vega-lite uses top-level await (can't be CJS bundled)
+                .filter((module) => !['zeromq', 'zeromqold', 'vscode-jsonrpc', 'vega-lite'].includes(module))
 
                 .map(async (module) => {
                     const fullPath = require.resolve(module);
diff --git a/build/fix-directory-imports.mjs b/build/fix-directory-imports.mjs
deleted file mode 100644
index 8cea626f1a..0000000000
--- a/build/fix-directory-imports.mjs
+++ /dev/null
@@ -1,90 +0,0 @@
-#!/usr/bin/env node
-// Script to fix directory imports - convert './foo' to './foo/index.js' where foo is a directory
-
-import { promises as fs } from 'fs';
-import path from 'path';
-import { fileURLToPath } from 'url';
-import { dirname } from 'path';
-
-const __filename = fileURLToPath(import.meta.url);
-const __dirname = dirname(__filename);
-
-const rootDir = path.join(__dirname, '..');
-const srcDir = path.join(rootDir, 'src');
-
-// Known directory imports that need to be converted to /index.js
-const directoryImports = [
-    'platform/logging',
-    'telemetry',
-    'platform/pythonEnvironments/info',
-    'standalone/api'
-];
-
-async function getAllTsFiles(dir) {
-    const files = [];
-    const entries = await fs.readdir(dir, { withFileTypes: true });
-
-    for (const entry of entries) {
-        const fullPath = path.join(dir, entry.name);
-
-        if (entry.isDirectory()) {
-            if (!['node_modules', 'out', 'dist', '.git', '.vscode', 'resources'].includes(entry.name)) {
-                files.push(...(await getAllTsFiles(fullPath)));
-            }
-        } else if (entry.name.endsWith('.ts') || entry.name.endsWith('.tsx')) {
-            files.push(fullPath);
-        }
-    }
-
-    return files;
-}
-
-function fixDirectoryImports(content) {
-    let modified = content;
-    let changeCount = 0;
-
-    for (const dirImport of directoryImports) {
-        // Match imports with any relative path prefix (./, ../, ../../foo/, etc.)
-        // Captures: quote, prefix (e.g., './', '../../'), directoryImport, '.js', quote
-        const pattern = new RegExp(`(['"])((?:\\.\\.\\/|\\.\\/)(?:.*\\/)?)${dirImport}\\.js(['"])`, 'g');
-
-        const newModified = modified.replace(pattern, (match, quote1, prefix, quote2) => {
-            changeCount++;
-            return `${quote1}${prefix}${dirImport}/index.js${quote2}`;
-        });
-        modified = newModified;
-    }
-
-    return { content: modified, changed: changeCount > 0, changeCount };
-}
-
-async function main() {
-    console.log('🔍 Finding all TypeScript files in src/...');
-    const tsFiles = await getAllTsFiles(srcDir);
-    console.log(`📁 Found ${tsFiles.length} TypeScript files\n`);
-
-    let totalFilesChanged = 0;
-    let totalImportsFixed = 0;
-
-    for (const file of tsFiles) {
-        const content = await fs.readFile(file, 'utf-8');
-        const { content: newContent, changed, changeCount } = fixDirectoryImports(content);
-
-        if (changed) {
-            await fs.writeFile(file, newContent, 'utf-8');
-            totalFilesChanged++;
-            totalImportsFixed += changeCount;
-            const relativePath = path.relative(rootDir, file);
-            console.log(`✅ ${relativePath} (${changeCount} import${changeCount > 1 ? 's' : ''})`);
-        }
-    }
-
-    console.log(`\n✨ Done!`);
-    console.log(`📊 Modified ${totalFilesChanged} files`);
-    console.log(`🔗 Fixed ${totalImportsFixed} directory import${totalImportsFixed !== 1 ? 's' : ''}`);
-}
-
-main().catch(error => {
-    console.error('❌ Error:', error);
-    process.exit(1);
-});
diff --git a/build/mocha-esm-loader.js b/build/mocha-esm-loader.js
index 8e1d39d51a..153fdc306a 100644
--- a/build/mocha-esm-loader.js
+++ b/build/mocha-esm-loader.js
@@ -13,6 +13,40 @@ const projectRoot = path.join(__dirname, '..');
 const vscodeMockPath = pathToFileURL(path.join(projectRoot, 'out/test/vscode-mock.js')).href;
 const telemetryMockPath = pathToFileURL(path.join(projectRoot, 'out/test/mocks/vsc/telemetryReporter.js')).href;
 
+// Mock source for @vscode/python-extension - used in multiple places
+const PYTHON_EXTENSION_MOCK = `
+    // Mock PythonExtension class
+    export class PythonExtension {
+        static api() {
+            return Promise.resolve({
+                environments: {
+                    known: [],
+                    resolveEnvironment: () => Promise.resolve(undefined),
+                    onDidChangeEnvironments: { event: () => ({ dispose: () => {} }) }
+                }
+            });
+        }
+    }
+
+    // Mock Environment type (empty object, just for type compatibility)
+    export const Environment = {};
+
+    // Mock EnvironmentPath type
+    export const EnvironmentPath = {};
+
+    // Mock ResolvedEnvironment type
+    export const ResolvedEnvironment = {};
+
+    // Mock KnownEnvironmentTools
+    export const KnownEnvironmentTools = {};
+
+    // Mock KnownEnvironmentTypes
+    export const KnownEnvironmentTypes = {};
+
+    // Extension ID constant
+    export const PVSC_EXTENSION_ID = 'ms-python.python';
+`;
+
 import { stat } from 'node:fs/promises';
 
 /**
@@ -78,6 +112,16 @@ export async function resolve(specifier, context, nextResolve) {
         };
     }
 
+    // Intercept @vscode/python-extension - needed because it requires VS Code runtime
+    // Note: Only exact match is needed - no subpath imports (e.g., '@vscode/python-extension/foo')
+    // exist in the codebase. If subpath imports are added, change to startsWith() match.
+    if (specifier === '@vscode/python-extension') {
+        return {
+            url: 'vscode-mock:///python-extension',
+            shortCircuit: true
+        };
+    }
+
     // Handle extensionless imports (both relative and node_modules)
     return resolveWithFallback(specifier, context, nextResolve);
 }
@@ -346,10 +390,57 @@ export async function load(url, context, nextLoad) {
             };
         }
 
+        // Handle @vscode/python-extension mock - needed because it requires VS Code runtime
+        if (moduleName === 'python-extension') {
+            return {
+                format: 'module',
+                source: PYTHON_EXTENSION_MOCK,
+                shortCircuit: true
+            };
+        }
+
         // Unknown vscode-mock module
         throw new Error(`Unknown vscode-mock module: ${moduleName}`);
     }
 
+    // Handle @vscode/python-extension - it's a CJS module that esmock tries to load directly
+    // We intercept and return our mock to avoid CJS/ESM compatibility issues
+    // Use proper URL parsing and decoding to handle all encoding variants
+    try {
+        const urlObj = new URL(url);
+        const decodedPath = decodeURIComponent(urlObj.pathname);
+
+        if (decodedPath.includes('@vscode/python-extension') || decodedPath.includes('/@vscode/python-extension')) {
+            return {
+                format: 'module',
+                source: PYTHON_EXTENSION_MOCK,
+                shortCircuit: true
+            };
+        }
+    } catch {
+        // If URL parsing fails, fall through to other handlers
+    }
+
+    // For .js files in the out/ directory, inject CJS globals shims
+    // This is needed because source files use native __dirname, __filename, require which don't exist in ESM
+    if (url.startsWith('file://') && url.includes('/out/') && url.endsWith('.js')) {
+        const filePath = fileURLToPath(url);
+        const fs = await import('node:fs/promises');
+        const source = await fs.readFile(filePath, 'utf8');
+        const shim = `import { fileURLToPath as __fileURLToPath } from 'url';
+import { dirname as __getDirname } from 'path';
+import { createRequire as __createRequire } from 'module';
+const __filename = __fileURLToPath(import.meta.url);
+const __dirname = __getDirname(__filename);
+const require = __createRequire(import.meta.url);
+`;
+        return {
+            format: 'module',
+            source: shim + source,
+            shortCircuit: true
+        };
+    }
+
     // Let Node.js handle all other URLs
     return nextLoad(url, context);
 }
diff --git a/build/remove-js-extensions.mjs b/build/remove-js-extensions.mjs
deleted file mode 100644
index a1a47c8d69..0000000000
--- a/build/remove-js-extensions.mjs
+++ /dev/null
@@ -1,87 +0,0 @@
-#!/usr/bin/env node
-// Script to remove .js extensions from relative imports in TypeScript files
-// This is for bundler-based module resolution where extensions are not needed
-
-import { promises as fs } from 'fs';
-import path from 'path';
-import { fileURLToPath } from 'url';
-
-const __filename = fileURLToPath(import.meta.url);
-const __dirname = path.dirname(__filename);
-
-const rootDir = path.join(__dirname, '..');
-const srcDir = path.join(rootDir, 'src');
-
-async function getAllTsFiles(dir) {
-    const files = [];
-    const entries = await fs.readdir(dir, { withFileTypes: true });
-
-    for (const entry of entries) {
-        const fullPath = path.join(dir, entry.name);
-
-        if (entry.isDirectory()) {
-            if (!['node_modules', 'out', 'dist', '.git', '.vscode', 'resources'].includes(entry.name)) {
-                files.push(...(await getAllTsFiles(fullPath)));
-            }
-        } else if ((entry.name.endsWith('.ts') || entry.name.endsWith('.tsx')) && !entry.name.endsWith('.d.ts')) {
-            files.push(fullPath);
-        }
-    }
-
-    return files;
-}
-
-function removeJsExtensions(content) {
-    let modified = content;
-    let changeCount = 0;
-
-    // Pattern to match relative imports with .js extension
-    // Matches: from './foo.js' or from '../bar/index.js'
-    // Does NOT match: from 'package-name' or from 'node:fs'
-    const patterns = [
-        // import ... from './path.js' or '../path.js'
-        /(\bfrom\s+['"])(\.\/?[^'"]+)\.js(['"])/g,
-        // import('./path.js') or import('../path.js')
-        /(\bimport\s*\(\s*['"])(\.\/?[^'"]+)\.js(['"])/g
-    ];
-
-    for (const pattern of patterns) {
-        modified = modified.replace(pattern, (match, before, importPath, after) => {
-            changeCount++;
-            return `${before}${importPath}${after}`;
-        });
-    }
-
-    return { content: modified, changed: changeCount > 0, changeCount };
-}
-
-async function main() {
-    console.log('🔍 Finding all TypeScript files in src/...');
-    const tsFiles = await getAllTsFiles(srcDir);
-    console.log(`📁 Found ${tsFiles.length} TypeScript files\n`);
-
-    let totalFilesChanged = 0;
-    let totalExtensionsRemoved = 0;
-
-    for (const file of tsFiles) {
-        const content = await fs.readFile(file, 'utf-8');
-        const { content: newContent, changed, changeCount } = removeJsExtensions(content);
-
-        if (changed) {
-            await fs.writeFile(file, newContent, 'utf-8');
-            totalFilesChanged++;
-            totalExtensionsRemoved += changeCount;
-            const relativePath = path.relative(rootDir, file);
-            console.log(`✅ ${relativePath} (${changeCount} extension${changeCount > 1 ? 's' : ''})`);
-        }
-    }
-
-    console.log(`\n✨ Done!`);
-    console.log(`📊 Modified ${totalFilesChanged} files`);
-    console.log(`🔗 Removed ${totalExtensionsRemoved} .js extension${totalExtensionsRemoved !== 1 ? 's' : ''}`);
-}
-
-main().catch((error) => {
-    console.error('❌ Error:', error);
-    process.exit(1);
-});
diff --git a/package-lock.json b/package-lock.json
index becead4792..1be4df041e 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -43,7 +43,7 @@
                 "isomorphic-ws": "^4.0.1",
                 "jquery": "^3.6.0",
                 "js-yaml": "^4.1.1",
-                "jsonc-parser": "^2.0.3",
+                "jsonc-parser": "3.3.1",
                 "lodash": "^4.17.21",
                 "marked": "^4.0.10",
                 "node-fetch": "^2.6.7",
@@ -17352,9 +17352,10 @@
             }
         },
         "node_modules/jsonc-parser": {
-            "version": "2.3.1",
-            "resolved": "https://registry.npmjs.org/jsonc-parser/-/jsonc-parser-2.3.1.tgz",
-            "integrity": "sha512-H8jvkz1O50L3dMZCsLqiuB2tA7muqbSg1AtGEkN0leAqGjsUzDJir3Zwr02BhqdcITPg3ei3mZ+HjMocAknhhg=="
+            "version": "3.3.1",
+            "resolved": "https://registry.npmjs.org/jsonc-parser/-/jsonc-parser-3.3.1.tgz",
+            "integrity": "sha512-HUgH65KyejrUFPvHFPbqOY0rsFip3Bo5wb4ngvdi1EpCYWUQDC5V+Y7mZws+DLkr4M//zQJoanu1SP+87Dv1oQ==",
+            "license": "MIT"
         },
         "node_modules/jsonfile": {
             "version": "4.0.0",
@@ -39838,9 +39839,9 @@
             "integrity": "sha512-XmOWe7eyHYH14cLdVPoyg+GOH3rYX++KpzrylJwSW98t3Nk+U8XOl8FWKOgwtzdb8lXGf6zYwDUzeHMWfxasyg=="
         },
         "jsonc-parser": {
-            "version": "2.3.1",
-            "resolved": "https://registry.npmjs.org/jsonc-parser/-/jsonc-parser-2.3.1.tgz",
-            "integrity": "sha512-H8jvkz1O50L3dMZCsLqiuB2tA7muqbSg1AtGEkN0leAqGjsUzDJir3Zwr02BhqdcITPg3ei3mZ+HjMocAknhhg=="
+            "version": "3.3.1",
+            "resolved": "https://registry.npmjs.org/jsonc-parser/-/jsonc-parser-3.3.1.tgz",
+            "integrity": "sha512-HUgH65KyejrUFPvHFPbqOY0rsFip3Bo5wb4ngvdi1EpCYWUQDC5V+Y7mZws+DLkr4M//zQJoanu1SP+87Dv1oQ=="
         },
         "jsonfile": {
             "version": "4.0.0",
diff --git a/package.json b/package.json
index 77c50472bb..f314a4af85 100644
--- a/package.json
+++ b/package.json
@@ -2,7 +2,6 @@
     "name": "vscode-deepnote",
     "displayName": "Deepnote",
     "version": "1.2.0",
-    "type": "module",
     "description": "Deepnote notebook support.",
     "publisher": "Deepnote",
     "author": {
@@ -62,7 +61,7 @@
         "onNotebook:deepnote",
         "onNotebook:interactive"
     ],
-    "main": "./dist/extension.node.proxy.js",
+    "main": "./dist/extension.node.js",
     "browser": "./dist/extension.web.bundle.js",
     "capabilities": {
         "virtualWorkspaces": true,
@@ -2533,7 +2532,7 @@
         "isomorphic-ws": "^4.0.1",
         "jquery": "^3.6.0",
         "js-yaml": "^4.1.1",
-        "jsonc-parser": "^2.0.3",
+        "jsonc-parser": "3.3.1",
         "lodash": "^4.17.21",
         "marked": "^4.0.10",
         "node-fetch": "^2.6.7",
diff --git a/src/extension.node.proxy.ts b/src/extension.node.proxy.ts
deleted file mode 100644
index 0922f2ccf8..0000000000
--- a/src/extension.node.proxy.ts
+++ /dev/null
@@ -1,34 +0,0 @@
-// Copyright (c) Microsoft Corporation.
-// Licensed under the MIT License.
-
-import type { IExtensionApi } from './standalone/api';
-import type { IExtensionContext } from './platform/common/types';
-import { ExtensionMode } from 'vscode';
-
-let realEntryPoint: {
-    activate: typeof activate;
-    deactivate: typeof deactivate;
-};
-
-export async function activate(context: IExtensionContext): Promise<IExtensionApi> {
-    // Use dynamic path construction to prevent esbuild from bundling the module
-    // Must use explicit './' prefix for ESM imports to work correctly
-    const entryPoint =
-        context.extensionMode === ExtensionMode.Test ? '../out/extension.node.js' : './extension.node.js';
-    try {
-        realEntryPoint = await import(/* webpackIgnore: true */ entryPoint);
-        return realEntryPoint.activate(context);
-    } catch (ex) {
-        if (!ex.toString().includes(`Cannot find module '../out/extension.node.js'`)) {
-            console.error('Failed to activate extension, falling back to `./extension.node.js`', ex);
-        }
-        // In smoke tests, we do not want to load the out/extension.node.
-        const fallbackPath = './extension.node.js';
-        realEntryPoint = await import(/* webpackIgnore: true */ fallbackPath);
-        return realEntryPoint.activate(context);
-    }
-}
-
-export function deactivate(): Thenable<void> {
-    return realEntryPoint.deactivate();
-}
diff --git a/src/kernels/deepnote/deepnoteLspClientManager.node.ts b/src/kernels/deepnote/deepnoteLspClientManager.node.ts
index 227e29bda2..8389da4bad 100644
--- a/src/kernels/deepnote/deepnoteLspClientManager.node.ts
+++ b/src/kernels/deepnote/deepnoteLspClientManager.node.ts
@@ -2,7 +2,6 @@ import * as fs from 'fs';
 import * as vscode from 'vscode';
 import { CancellationError } from 'vscode';
 import { inject, injectable } from 'inversify';
-import { createRequire } from 'module';
 import type {
     LanguageClient as LanguageClientType,
     LanguageClientOptions,
@@ -10,9 +9,8 @@ import type {
     ServerOptions
 } from 'vscode-languageclient/node';
 
-// Use createRequire for ESM compatibility with vscode-languageclient
 // The bundled module uses ESM default export, so we need to access .default
-const require = createRequire(import.meta.url);
+// eslint-disable-next-line @typescript-eslint/no-require-imports
 const languageClientModule = require('vscode-languageclient/node');
 const { LanguageClient, TransportKind, RevealOutputChannelOn } = (languageClientModule.default ??
     languageClientModule) as typeof import('vscode-languageclient/node');
@@ -543,6 +541,7 @@ export class DeepnoteLspClientManager
     private getSqlLanguageServerModule(): string {
         // Try require.resolve first - this handles different package layouts (works in dev mode)
         try {
+            // eslint-disable-next-line @typescript-eslint/no-require-imports
             const serverModule = require.resolve('@deepnote/sql-language-server/dist/bin/vscodeExtensionServer.js');
 
             logger.trace('SQL LSP server module resolved via require.resolve:', serverModule);
diff --git a/src/kernels/raw/finder/jupyterPaths.node.unit.test.ts b/src/kernels/raw/finder/jupyterPaths.node.unit.test.ts
index cb3b9a0505..de268848a7 100644
--- a/src/kernels/raw/finder/jupyterPaths.node.unit.test.ts
+++ b/src/kernels/raw/finder/jupyterPaths.node.unit.test.ts
@@ -18,7 +18,6 @@ import { ICustomEnvironmentVariablesProvider } from '../../../platform/common/va
 import { IPythonExecutionService, IPythonExecutionFactory } from '../../../platform/interpreter/types.node';
 import { PythonEnvironment } from '../../../platform/pythonEnvironments/info';
 import * as path from '../../../platform/vscode-path/path';
-import { getFilename } from '../../../platform/common/esmUtils.node';
 import { EXTENSION_ROOT_DIR_FOR_TESTS } from '../../../test/constants.node';
 import { resolvableInstance, uriEquals } from '../../../test/datascience/helpers';
 import { IInterpreterService } from '../../../platform/interpreter/contracts';
@@ -338,7 +337,7 @@ suite('Jupyter Paths', () => {
         when(platformService.osType).thenReturn(OSType.Windows);
         when(platformService.homeDir).thenReturn(windowsHomeDir);
         when(memento.get(CACHE_KEY_FOR_JUPYTER_KERNEL_PATHS, anything())).thenReturn([]);
-        const jupyter_Paths = [getFilename(import.meta.url)];
+        const jupyter_Paths = [__filename];
         process.env['JUPYTER_PATH'] = jupyter_Paths.join(path.delimiter);
 
         const paths = await jupyterPaths.getKernelSpecRootPaths(cancelToken.token);
@@ -348,10 +347,7 @@ suite('Jupyter Paths', () => {
         assert.strictEqual(paths.length, 3, `Expected 3 paths, got ${paths.length}, ${JSON.stringify(paths)}`);
 
         // First path should be from JUPYTER_PATH
-        assert.strictEqual(
-            paths[0].toString(),
-            Uri.joinPath(Uri.file(getFilename(import.meta.url)), 'kernels').toString()
-        );
+        assert.strictEqual(paths[0].toString(), Uri.joinPath(Uri.file(__filename), 'kernels').toString());
 
         // Second path should be from data directory (.jupyter/data/kernels)
         assert.strictEqual(paths[1].toString(), Uri.joinPath(windowsHomeDir, '.jupyter', 'data', 'kernels').toString());
@@ -363,7 +359,7 @@ suite('Jupyter Paths', () => {
         when(platformService.osType).thenReturn(OSType.Windows);
         when(platformService.homeDir).thenReturn(windowsHomeDir);
         when(memento.get(CACHE_KEY_FOR_JUPYTER_KERNEL_PATHS, anything())).thenReturn([]);
-        const jupyter_Paths = [getFilename(import.meta.url)];
+        const jupyter_Paths = [__filename];
         process.env['JUPYTER_PATH'] = jupyter_Paths.join(path.delimiter);
         const allUserProfilePath = (process.env['PROGRAMDATA'] = path.join(EXTENSION_ROOT_DIR_FOR_TESTS, 'temp'));
 
@@ -374,10 +370,7 @@ suite('Jupyter Paths', () => {
         assert.strictEqual(paths.length, 4, `Expected 4 paths, got ${paths.length}, ${JSON.stringify(paths)}`);
 
         // First path should be from JUPYTER_PATH
-        assert.strictEqual(
-            paths[0].toString(),
-            Uri.joinPath(Uri.file(getFilename(import.meta.url)), 'kernels').toString()
-        );
+        assert.strictEqual(paths[0].toString(), Uri.joinPath(Uri.file(__filename), 'kernels').toString());
 
         // Second path should be from data directory (.jupyter/data/kernels)
         assert.strictEqual(paths[1].toString(), Uri.joinPath(windowsHomeDir, '.jupyter', 'data', 'kernels').toString());
diff --git a/src/kernels/raw/launcher/kernelLauncher.unit.test.ts b/src/kernels/raw/launcher/kernelLauncher.unit.test.ts
index 4d0f6bad82..2284e1ea8c 100644
--- a/src/kernels/raw/launcher/kernelLauncher.unit.test.ts
+++ b/src/kernels/raw/launcher/kernelLauncher.unit.test.ts
@@ -29,9 +29,6 @@ import { KernelProcess } from './kernelProcess.node';
 import { IPythonExecutionFactory, IPythonExecutionService } from '../../../platform/interpreter/types.node';
 import { UsedPorts } from '../../common/usedPorts';
 import { mockedVSCodeNamespaces, resetVSCodeMocks } from '../../../test/vscode-mock';
-import { getDirname } from '../../../platform/common/esmUtils.node';
-
-const __dirname = getDirname(import.meta.url);
 
 suite('kernel Launcher', () => {
     let disposables: IDisposable[] = [];
diff --git a/src/kernels/raw/launcher/kernelProcess.node.unit.test.ts b/src/kernels/raw/launcher/kernelProcess.node.unit.test.ts
index ff614303cc..3d7991bdd3 100644
--- a/src/kernels/raw/launcher/kernelProcess.node.unit.test.ts
+++ b/src/kernels/raw/launcher/kernelProcess.node.unit.test.ts
@@ -38,9 +38,7 @@ import { waitForCondition } from '../../../test/common.node';
 import { IS_REMOTE_NATIVE_TEST } from '../../../test/constants';
 import { logger } from '../../../platform/logging';
 import { IPlatformService } from '../../../platform/common/platform/types';
-import { getDirname } from '../../../platform/common/esmUtils.node';
 
-const __dirname = getDirname(import.meta.url);
 import { IPythonExecutionFactory, IPythonExecutionService } from '../../../platform/interpreter/types.node';
 import { createObservable } from '../../../platform/common/process/proc.node';
 import { ServiceContainer } from '../../../platform/ioc/container';
diff --git a/src/kernels/raw/session/rawSessionConnection.node.unit.test.ts b/src/kernels/raw/session/rawSessionConnection.node.unit.test.ts
index 2b42dbe4f8..3ab48b0b03 100644
--- a/src/kernels/raw/session/rawSessionConnection.node.unit.test.ts
+++ b/src/kernels/raw/session/rawSessionConnection.node.unit.test.ts
@@ -31,12 +31,9 @@ import { KernelConnectionTimeoutError } from '../../errors/kernelConnectionTimeo
 import { mockedVSCodeNamespaces, resetVSCodeMocks } from '../../../test/vscode-mock';
 import type { IFileSystem } from '../../../platform/common/platform/types';
 import { computeLocalWorkingDirectory } from './kernelWorkingDirectory.node';
-import { createRequire } from 'module';
-import { getDirname } from '../../../platform/common/esmUtils.node';
 import esmock from 'esmock';
 
-const __dirname = getDirname(import.meta.url);
-const require = createRequire(import.meta.url);
+// eslint-disable-next-line @typescript-eslint/no-require-imports
 const jupyterLabKernel =
     require('@jupyterlab/services/lib/kernel/default') as typeof import('@jupyterlab/services/lib/kernel/default');
 
diff --git a/src/kernels/raw/session/zeromq.node.ts b/src/kernels/raw/session/zeromq.node.ts
index 17fb07e108..0c9023852a 100644
--- a/src/kernels/raw/session/zeromq.node.ts
+++ b/src/kernels/raw/session/zeromq.node.ts
@@ -9,13 +9,11 @@ import { Telemetry, sendTelemetryEvent } from '../../../telemetry';
 import { noop } from '../../../platform/common/utils/misc';
 import { DistroInfo, getDistroInfo } from '../../../platform/common/platform/linuxDistro.node';
 import { EXTENSION_ROOT_DIR } from '../../../platform/constants.node';
-import { createRequire } from 'module';
 
-// Use createRequire for dynamic loading of zeromq, which is a native module
-const require = createRequire(import.meta.url);
 const zeromqModuleName = `${'zeromq'}`;
 export function getZeroMQ(): typeof import('zeromq') {
     try {
+        // eslint-disable-next-line @typescript-eslint/no-require-imports
         const zmq: typeof import('zeromq') = require(zeromqModuleName);
         // We do not want to block the process from exiting if there are any pending messages.
         zmq.context.blocky = false;
@@ -23,6 +21,7 @@ export function getZeroMQ(): typeof import('zeromq') {
         return zmq;
     } catch (e) {
         try {
+            // eslint-disable-next-line @typescript-eslint/no-require-imports
             const zmq = require(path.join(EXTENSION_ROOT_DIR, 'dist', 'node_modules', 'zeromqold'));
             logger.info('ZMQ loaded via fallback mechanism.');
             sendZMQTelemetry(false, true, e.message || e.toString()).catch(noop);
diff --git a/src/notebooks/controllers/ipywidgets/scriptSourceProvider/localWidgetScriptSourceProvider.unit.test.ts b/src/notebooks/controllers/ipywidgets/scriptSourceProvider/localWidgetScriptSourceProvider.unit.test.ts
index e95b6cf995..978e071a23 100644
--- a/src/notebooks/controllers/ipywidgets/scriptSourceProvider/localWidgetScriptSourceProvider.unit.test.ts
+++ b/src/notebooks/controllers/ipywidgets/scriptSourceProvider/localWidgetScriptSourceProvider.unit.test.ts
@@ -12,9 +12,6 @@ import {
     IIPyWidgetScriptManager
 } from '../types';
 import { LocalWidgetScriptSourceProvider } from './localWidgetScriptSourceProvider.node';
-import { getDirname } from '../../../../platform/common/esmUtils.node';
-
-const __dirname = getDirname(import.meta.url);
 
 /* eslint-disable , @typescript-eslint/no-explicit-any */
 suite('ipywidget - Local Widget Script Source', () => {
diff --git a/src/notebooks/controllers/ipywidgets/scriptSourceProvider/nbExtensionsPathProvider.unit.test.ts b/src/notebooks/controllers/ipywidgets/scriptSourceProvider/nbExtensionsPathProvider.unit.test.ts
index c976cd3ad8..6a8611c3e4 100644
--- a/src/notebooks/controllers/ipywidgets/scriptSourceProvider/nbExtensionsPathProvider.unit.test.ts
+++ b/src/notebooks/controllers/ipywidgets/scriptSourceProvider/nbExtensionsPathProvider.unit.test.ts
@@ -23,9 +23,6 @@ import { NbExtensionsPathProvider as WebNbExtensionsPathProvider } from './nbExt
 import { PythonExtension } from '@vscode/python-extension';
 import { resolvableInstance } from '../../../../test/datascience/helpers';
 import { dispose } from '../../../../platform/common/utils/lifecycle';
-import { getDirname } from '../../../../platform/common/esmUtils.node';
-
-const __dirname = getDirname(import.meta.url);
 
 [false, true].forEach((isWeb) => {
     const localNonPythonKernelSpec = LocalKernelSpecConnectionMetadata.create({
diff --git a/src/notebooks/deepnote/deepnoteDataConverter.ts b/src/notebooks/deepnote/deepnoteDataConverter.ts
index 8f81d9c431..a9bffc365b 100644
--- a/src/notebooks/deepnote/deepnoteDataConverter.ts
+++ b/src/notebooks/deepnote/deepnoteDataConverter.ts
@@ -8,7 +8,7 @@ import { CodeBlockConverter } from './converters/codeBlockConverter';
 import { addPocketToCellMetadata, createBlockFromPocket } from '../../platform/deepnote/pocket';
 import { MarkdownBlockConverter } from './converters/markdownBlockConverter';
 import { VisualizationBlockConverter } from './converters/visualizationBlockConverter';
-import { compile as convertVegaLiteSpecToVega } from 'vega-lite';
+import { compile as convertVegaLiteSpecToVega, ensureVegaLiteLoaded } from './vegaLiteWrapper';
 import { produce } from 'immer';
 import { SqlBlockConverter } from './converters/sqlBlockConverter';
 import { TextBlockConverter } from './converters/textBlockConverter';
@@ -54,6 +54,14 @@ export class DeepnoteDataConverter {
         this.registry.register(new VisualizationBlockConverter());
     }
 
+    /**
+     * Initialize async dependencies like vega-lite.
+     * Must be called before using output conversion methods.
+     */
+    async initialize(): Promise<void> {
+        await ensureVegaLiteLoaded();
+    }
+
     /**
      * Finds a converter for the given block type.
      * @param blockType The type of block to find a converter for
@@ -395,8 +403,13 @@ export class DeepnoteDataConverter {
                                 draft.config.customFormatTypes = true;
                             });
 
-                            const vegaSpec = convertVegaLiteSpecToVega(patchedVegaLiteSpec as VegaLiteSpec).spec;
-                            items.push(NotebookCellOutputItem.json(vegaSpec, 'application/vnd.vega.v6+json'));
+                            const vegaResult = convertVegaLiteSpecToVega(patchedVegaLiteSpec as VegaLiteSpec);
+
+                            if (vegaResult) {
+                                items.push(
+                                    NotebookCellOutputItem.json(vegaResult.spec, 'application/vnd.vega.v6+json')
+                                );
+                            }
                         }
 
                         if (data['application/json']) {
diff --git a/src/notebooks/deepnote/deepnoteSerializer.ts b/src/notebooks/deepnote/deepnoteSerializer.ts
index aa3832613d..6216a57628 100644
--- a/src/notebooks/deepnote/deepnoteSerializer.ts
+++ b/src/notebooks/deepnote/deepnoteSerializer.ts
@@ -75,6 +75,13 @@ export class DeepnoteNotebookSerializer implements NotebookSerializer {
             throw new Error('Serialization cancelled');
         }
 
+        // Initialize vega-lite for output conversion (lazy-loaded ESM module)
+        await this.converter.initialize();
+
+        if (token?.isCancellationRequested) {
+            throw new Error('Serialization cancelled');
+        }
+
         try {
             const contentString = new TextDecoder('utf-8').decode(content);
             const deepnoteFile = yaml.load(contentString) as DeepnoteFile;
diff --git a/src/notebooks/deepnote/vegaLiteWrapper.ts b/src/notebooks/deepnote/vegaLiteWrapper.ts
new file mode 100644
index 0000000000..f377c31abd
--- /dev/null
+++ b/src/notebooks/deepnote/vegaLiteWrapper.ts
@@ -0,0 +1,60 @@
+// Wrapper for vega-lite that uses dynamic import to handle ESM/CJS interop
+// vega-lite has top-level await (through vega-canvas) which isn't compatible with CJS bundles
+// This wrapper makes vega-lite optional - if it fails to load, we gracefully degrade
+
+import type { TopLevelSpec } from 'vega-lite';
+import type { Spec as VegaSpec } from 'vega';
+
+import { logger } from '../../platform/logging';
+
+let compileFunction: ((spec: TopLevelSpec) => { spec: VegaSpec }) | null = null;
+let loadPromise: Promise<void> | null = null;
+let loadFailed = false;
+
+async function loadVegaLite(): Promise<void> {
+    if (typeof compileFunction === 'function' || loadFailed) return;
+    if (loadPromise) return loadPromise;
+
+    loadPromise = (async () => {
+        try {
+            const vegaLite = await import('vega-lite');
+
+            if (!vegaLite.compile || typeof vegaLite.compile !== 'function') {
+                throw new Error(
+                    `vega-lite module loaded but compile function is missing or not a function. Got: ${typeof vegaLite.compile}. Vega-lite chart conversion will be skipped.`
+                );
+            }
+
+            compileFunction = vegaLite.compile;
+        } catch (error) {
+            compileFunction = null;
+            loadFailed = true;
+            logger.warn('vega-lite could not be loaded. Vega-lite chart conversion will be skipped.', error);
+        }
+    })();
+
+    return loadPromise;
+}
+
+/**
+ * Check if vega-lite is available for use.
+ */
+export function isVegaLiteAvailable(): boolean {
+    return typeof compileFunction === 'function';
+}
+
+/**
+ * Compile a vega-lite spec to a vega spec.
+ * Returns undefined if vega-lite is not available.
+ */
+export function compile(spec: TopLevelSpec): { spec: VegaSpec } | undefined {
+    if (typeof compileFunction !== 'function') {
+        return undefined;
+    }
+
+    return compileFunction(spec);
+}
+
+export async function ensureVegaLiteLoaded(): Promise<void> {
+    await loadVegaLite();
+}
diff --git a/src/notebooks/notebookEnvironmentService.node.ts b/src/notebooks/notebookEnvironmentService.node.ts
index 3cfdc05cba..28ad68f62d 100644
--- a/src/notebooks/notebookEnvironmentService.node.ts
+++ b/src/notebooks/notebookEnvironmentService.node.ts
@@ -16,7 +16,6 @@ import { getCachedEnvironment, getInterpreterInfo } from '../platform/interprete
 import type { Environment, EnvironmentPath } from '@vscode/python-extension';
 import type { PythonEnvironment } from '../platform/pythonEnvironments/info';
 import { toPythonSafePath } from '../platform/common/utils/encoder';
-import { getFilename } from '../platform/common/esmUtils.node';
 
 @injectable()
 export class NotebookPythonEnvironmentService extends DisposableBase implements INotebookPythonEnvironmentService {
@@ -154,7 +153,7 @@ import os as _VSCODE_os
 import sys as _VSCODE_sys
 import builtins as _VSCODE_builtins
 
-if _VSCODE_os.path.exists(${toPythonSafePath(getFilename(import.meta.url))}):
+if _VSCODE_os.path.exists(${toPythonSafePath(__filename)}):
     _VSCODE_builtins.print(f"EXECUTABLE{_VSCODE_sys.executable}EXECUTABLE")
 
 del _VSCODE_os, _VSCODE_sys, _VSCODE_builtins
diff --git a/src/platform/common/esmUtils.node.ts b/src/platform/common/esmUtils.node.ts
deleted file mode 100644
index d05c807d75..0000000000
--- a/src/platform/common/esmUtils.node.ts
+++ /dev/null
@@ -1,24 +0,0 @@
-// Copyright (c) Deepnote. All rights reserved.
-// Licensed under the MIT License.
-
-import { fileURLToPath } from 'url';
-// eslint-disable-next-line local-rules/node-imports
-import { dirname } from 'path';
-
-/**
- * Get the directory name equivalent to __dirname in ESM context.
- * @param importMetaUrl - Pass import.meta.url
- * @returns The directory path
- */
-export function getDirname(importMetaUrl: string): string {
-    return dirname(fileURLToPath(importMetaUrl));
-}
-
-/**
- * Get the file name equivalent to __filename in ESM context.
- * @param importMetaUrl - Pass import.meta.url
- * @returns The file path
- */
-export function getFilename(importMetaUrl: string): string {
-    return fileURLToPath(importMetaUrl);
-}
diff --git a/src/platform/common/variables/systemVariables.node.ts b/src/platform/common/variables/systemVariables.node.ts
index e410fea45f..94a741a61a 100644
--- a/src/platform/common/variables/systemVariables.node.ts
+++ b/src/platform/common/variables/systemVariables.node.ts
@@ -7,7 +7,6 @@ import * as path from '../../vscode-path/path';
 import { Uri, Range, workspace, window } from 'vscode';
 import { AbstractSystemVariables } from './systemVariables';
 import { getUserHomeDir } from '../utils/platform.node';
-import { getDirname } from '../esmUtils.node';
 
 /**
  * System variables for node.js. Node specific is necessary because of using the current process environment.
@@ -24,9 +23,7 @@ export class SystemVariables extends AbstractSystemVariables {
     constructor(file: Uri | undefined, rootFolder: Uri | undefined) {
         super();
         const workspaceFolder = file ? workspace.getWorkspaceFolder(file) : undefined;
-        this._workspaceFolder = workspaceFolder
-            ? workspaceFolder.uri.fsPath
-            : rootFolder?.fsPath || getDirname(import.meta.url);
+        this._workspaceFolder = workspaceFolder ? workspaceFolder.uri.fsPath : rootFolder?.fsPath || __dirname;
         this._workspaceFolderName = path.basename(this._workspaceFolder);
         this._fileWorkspaceFolder = this._workspaceFolder;
         this._filePath = file ? file.fsPath : undefined;
diff --git a/src/platform/constants.node.ts b/src/platform/constants.node.ts
index 8e19a4f792..b8f1b5613d 100644
--- a/src/platform/constants.node.ts
+++ b/src/platform/constants.node.ts
@@ -2,12 +2,6 @@
 // Licensed under the MIT License.
 
 import * as path from './vscode-path/path';
-import { createRequire } from 'module';
-
-import { getDirname } from './common/esmUtils.node';
-
-const require = createRequire(import.meta.url);
-const __dirname = getDirname(import.meta.url);
 
 // We always use esbuild to bundle the extension,
 // Thus __dirname will always be a file in `dist` folder.
@@ -19,6 +13,7 @@ export * from './constants';
 // Override isPreReleaseVersion with Node.js-specific implementation
 export function isPreReleaseVersion(): boolean {
     try {
+        // eslint-disable-next-line @typescript-eslint/no-require-imports
         const { isPreRelease } = require('vscode-jupyter-release-version') as { isPreRelease?: boolean };
         return isPreRelease === true;
     } catch {
diff --git a/src/platform/interpreter/filter/completionProvider.node.ts b/src/platform/interpreter/filter/completionProvider.node.ts
index 3f994b80eb..40ce0213f3 100644
--- a/src/platform/interpreter/filter/completionProvider.node.ts
+++ b/src/platform/interpreter/filter/completionProvider.node.ts
@@ -75,6 +75,9 @@ export class PythonEnvFilterCompletionProvider implements CompletionItemProvider
             const settings = document.getText();
             const location = getLocation(settings, document.offsetAt(position));
             const root = parseTree(settings);
+            if (!root) {
+                return [];
+            }
             const settingsNode = findNodeAtLocation(root, [location.path[0]]);
             if (!settingsNode) {
                 return [];
diff --git a/src/test/analysisEngineTest.node.ts b/src/test/analysisEngineTest.node.ts
index c0377950c5..125fbca1f2 100644
--- a/src/test/analysisEngineTest.node.ts
+++ b/src/test/analysisEngineTest.node.ts
@@ -3,9 +3,6 @@
 
 /* eslint-disable no-console, @typescript-eslint/no-require-imports, @typescript-eslint/no-var-requires */
 import * as path from '../platform/vscode-path/path';
-import { getDirname } from '../platform/common/esmUtils.node';
-
-const __dirname = getDirname(import.meta.url);
 
 process.env.CODE_TESTS_WORKSPACE = path.join(__dirname, '..', '..', 'src', 'test');
 process.env.IS_CI_SERVER_TEST_DEBUGGER = '';
diff --git a/src/test/common.node.ts b/src/test/common.node.ts
index 21818f75ae..d5c961222f 100644
--- a/src/test/common.node.ts
+++ b/src/test/common.node.ts
@@ -20,9 +20,6 @@ import * as vscode from 'vscode';
 import * as configSettings from '../platform/common/configSettings';
 import * as initializeModule from './initialize.node';
 import StreamZip from 'node-stream-zip';
-import { getDirname } from '../platform/common/esmUtils.node';
-
-const __dirname = getDirname(import.meta.url);
 
 export { createEventHandler } from './common';
 
diff --git a/src/test/common/variables/envVarsService.vscode.test.ts b/src/test/common/variables/envVarsService.vscode.test.ts
index ce424efc95..bb83302786 100644
--- a/src/test/common/variables/envVarsService.vscode.test.ts
+++ b/src/test/common/variables/envVarsService.vscode.test.ts
@@ -10,9 +10,6 @@ import { FileSystem } from '../../../platform/common/platform/fileSystem.node';
 import { EnvironmentVariablesService } from '../../../platform/common/variables/environment.node';
 import { IEnvironmentVariablesService } from '../../../platform/common/variables/types';
 import { initialize } from '../../initialize';
-import { getDirname } from '../../../platform/common/esmUtils.node';
-
-const __dirname = getDirname(import.meta.url);
 
 use(chaiAsPromised);
 
diff --git a/src/test/constants.node.ts b/src/test/constants.node.ts
index 88e5da60c6..7ec3de79dc 100644
--- a/src/test/constants.node.ts
+++ b/src/test/constants.node.ts
@@ -4,12 +4,9 @@
 import * as path from '../platform/vscode-path/path';
 import { setCI, setTestExecution, setUnitTestExecution } from '../platform/common/constants';
 import { setTestSettings } from './constants';
-import { getDirname } from '../platform/common/esmUtils.node';
 export * from './constants';
 
 // Activating extension for Multiroot and Debugger CI tests for Windows takes just over 2 minutes sometimes, so 3 minutes seems like a safe margin
-
-const __dirname = getDirname(import.meta.url);
 export const EXTENSION_ROOT_DIR_FOR_TESTS = path.join(__dirname, '..', '..');
 export const EXTENSION_TEST_DIR_FOR_FILES = path.join(
     EXTENSION_ROOT_DIR_FOR_TESTS,
diff --git a/src/test/debuggerTest.node.ts b/src/test/debuggerTest.node.ts
index 912007422f..823b85f87d 100644
--- a/src/test/debuggerTest.node.ts
+++ b/src/test/debuggerTest.node.ts
@@ -6,9 +6,6 @@
 import * as path from '../platform/vscode-path/path';
 import { runTests } from '@vscode/test-electron';
 import { EXTENSION_ROOT_DIR_FOR_TESTS } from './constants.node';
-import { getDirname } from '../platform/common/esmUtils.node';
-
-const __dirname = getDirname(import.meta.url);
 
 const workspacePath = path.join(__dirname, '..', '..', 'src', 'test', 'testMultiRootWkspc', 'multi.code-workspace');
 process.env.IS_CI_SERVER_TEST_DEBUGGER = '1';
diff --git a/src/test/extension.serviceRegistry.vscode.test.ts b/src/test/extension.serviceRegistry.vscode.test.ts
index 5e71b2b3f9..93584d4f4b 100644
--- a/src/test/extension.serviceRegistry.vscode.test.ts
+++ b/src/test/extension.serviceRegistry.vscode.test.ts
@@ -10,9 +10,6 @@ import * as ts from 'typescript';
 import * as fs from 'fs-extra';
 import glob from 'glob';
 import * as path from '../platform/vscode-path/path';
-import { getDirname } from '../platform/common/esmUtils.node';
-
-const __dirname = getDirname(import.meta.url);
 
 import { initialize } from './initialize.node';
 import { interfaces } from 'inversify/lib/interfaces/interfaces';
diff --git a/src/test/index.node.ts b/src/test/index.node.ts
index 24fa6cc74b..b6092000f4 100644
--- a/src/test/index.node.ts
+++ b/src/test/index.node.ts
@@ -28,9 +28,6 @@ import { stopJupyterServer } from './datascience/notebook/helper.node';
 import { initialize } from './initialize.node';
 import { rootHooks } from './testHooks.node';
 import { isCI } from '../platform/common/constants';
-import { getDirname } from '../platform/common/esmUtils.node';
-
-const __dirname = getDirname(import.meta.url);
 
 type SetupOptions = Mocha.MochaOptions & {
     testFilesSuffix: string;
diff --git a/src/test/pythonEnvironments/constants.ts b/src/test/pythonEnvironments/constants.ts
index b4b8579aa1..550311b3b3 100644
--- a/src/test/pythonEnvironments/constants.ts
+++ b/src/test/pythonEnvironments/constants.ts
@@ -4,9 +4,7 @@
 /* eslint-disable local-rules/dont-use-filename */
 
 import * as path from '../../platform/vscode-path/path';
-import { getDirname } from '../../platform/common/esmUtils.node';
 
-const __dirname = getDirname(import.meta.url);
 
 export const TEST_LAYOUT_ROOT = path.join(__dirname, '..', '..', '..', 'src', 'test', 'pythonEnvironments', 'common', 'envlayouts');
 
diff --git a/src/test/smokeTest.node.ts b/src/test/smokeTest.node.ts
index 7406ea7065..c182f702e9 100644
--- a/src/test/smokeTest.node.ts
+++ b/src/test/smokeTest.node.ts
@@ -12,9 +12,6 @@ import * as fs from 'fs-extra';
 import * as path from '../platform/vscode-path/path';
 import { unzip } from './common.node';
 import { EXTENSION_ROOT_DIR_FOR_TESTS, SMOKE_TEST_EXTENSIONS_DIR } from './constants.node';
-import { getDirname } from '../platform/common/esmUtils.node';
-
-const __dirname = getDirname(import.meta.url);
 
 class TestRunner {
     public async start() {
diff --git a/src/test/standardTest.node.ts b/src/test/standardTest.node.ts
index 58ec757759..e36da9f80c 100644
--- a/src/test/standardTest.node.ts
+++ b/src/test/standardTest.node.ts
@@ -10,9 +10,6 @@ import * as tmp from 'tmp';
 import { PythonExtension, setTestExecution, RendererExtension, isCI } from '../platform/common/constants';
 import { DownloadPlatform } from '@vscode/test-electron/out/download';
 import { arch } from 'os';
-import { getDirname } from '../platform/common/esmUtils.node';
-
-const __dirname = getDirname(import.meta.url);
 
 // Support for passing grep (specially for models or Copilot Coding Agent)
 // Local Copilot or Copilot Coding Agent can use `--grep=XYZ` or `--grep XYZ`
diff --git a/src/test/testRunner.ts b/src/test/testRunner.ts
index 88fc7982e9..621b0ab184 100644
--- a/src/test/testRunner.ts
+++ b/src/test/testRunner.ts
@@ -12,14 +12,9 @@ import { MAX_EXTENSION_ACTIVATION_TIME } from './constants.node';
 import { noop } from './core';
 import { stopJupyterServer } from './datascience/notebook/helper.node';
 import { initialize } from './initialize.node';
-import { createRequire } from 'module';
-import { getDirname } from '../platform/common/esmUtils.node';
-
-const __dirname = getDirname(import.meta.url);
 
 // Linux: prevent a weird NPE when mocha on Linux requires the window size from the TTY.
 // Since we are not running in a tty environment, we just implement the method statically.
-const require = createRequire(import.meta.url);
 const tty = require('tty');
 if (!tty.getWindowSize) {
     tty.getWindowSize = function (): number[] {
diff --git a/src/test/unittests.ts b/src/test/unittests.ts
index 62c5c56d70..a624856322 100644
--- a/src/test/unittests.ts
+++ b/src/test/unittests.ts
@@ -5,8 +5,8 @@
 import '../platform/ioc/reflectMetadata';
 
 // Set up CommonJS require hooks for mocking vscode in CJS modules
-import { createRequire } from 'module';
-const Module = createRequire(import.meta.url)('module');
+// eslint-disable-next-line @typescript-eslint/no-require-imports
+const Module = require('module');
 const originalLoad = Module._load;
 // We'll set up the hook after importing vscode-mock