diff --git a/.github/workflows/e2e-test.yml b/.github/workflows/e2e-test.yml
index ef5f163717..55e9dcee78 100644
--- a/.github/workflows/e2e-test.yml
+++ b/.github/workflows/e2e-test.yml
@@ -46,13 +46,12 @@ jobs:
         # via ConfigurationPage.createTestFile()) is still rendered in a
         # production build. Without it, e2e tests would time out waiting for
         # a button that was tree-shaken out.
+        # --skip-translations keeps VRT screenshots deterministic by rendering
+        # source-code English instead of upstream Weblate en.json (which can
+        # drift between snapshot capture and test runs).
         env:
           REACT_APP_NETLIFY: 'true'
-        run: |
-          yarn workspace plugins-service build
-          yarn workspace @actual-app/crdt build
-          yarn workspace @actual-app/core build:browser
-          yarn workspace @actual-app/web build:browser
+        run: yarn build:browser --skip-translations
       - name: Upload build artifact
         uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
         with:
diff --git a/.gitignore b/.gitignore
index f26446a5b9..83fc734300 100644
--- a/.gitignore
+++ b/.gitignore
@@ -42,6 +42,9 @@ bundle.desktop.js.map
 bundle.mobile.js
 bundle.mobile.js.map
 
+# Python virtualenv (Electron CI provisions one at the repo root for setuptools)
+.venv/
+
 # Yarn
 .pnp.*
 .yarn/*
diff --git a/bin/package-browser b/bin/package-browser
index fe6c178d1a..65ed276e8a 100755
--- a/bin/package-browser
+++ b/bin/package-browser
@@ -4,21 +4,30 @@ ROOT=`dirname $0`
 
 cd "$ROOT/.."
 
-echo "Updating translations..."
-if ! [ -d packages/desktop-client/locale ]; then
-    git clone https://github.com/actualbudget/translations packages/desktop-client/locale
+SKIP_TRANSLATIONS=false
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    --skip-translations)
+      SKIP_TRANSLATIONS=true
+      shift
+      ;;
+    *)
+      echo "Unknown argument: $1" >&2
+      exit 1
+      ;;
+  esac
+done
+
+if [ "$SKIP_TRANSLATIONS" = false ]; then
+  echo "Updating translations..."
+  if ! [ -d packages/desktop-client/locale ]; then
+      git clone https://github.com/actualbudget/translations packages/desktop-client/locale
+  fi
+  pushd packages/desktop-client/locale > /dev/null
+  git checkout .
+  git pull
+  popd > /dev/null
+  packages/desktop-client/bin/remove-untranslated-languages
 fi
-pushd packages/desktop-client/locale > /dev/null
-git checkout .
-git pull
-popd > /dev/null
-packages/desktop-client/bin/remove-untranslated-languages
 
-export NODE_OPTIONS="--max-old-space-size=4096"
-
-yarn workspace @actual-app/crdt build
-yarn workspace plugins-service build
-yarn workspace @actual-app/core build:browser
-yarn workspace @actual-app/web build:browser
-
-echo "packages/desktop-client/build"
+lage build:browser --to=@actual-app/web
diff --git a/bin/package-electron b/bin/package-electron
index 1525d29512..6e4fbd6d41 100755
--- a/bin/package-electron
+++ b/bin/package-electron
@@ -57,8 +57,7 @@ yarn workspace @actual-app/core build:node
 yarn workspace @actual-app/web build --mode=desktop # electron specific build
 
 # required for running the sync-server server
-yarn workspace @actual-app/core build:browser
-yarn workspace @actual-app/web build:browser
+yarn build:browser
 yarn workspace @actual-app/sync-server build
 
 # Emit @actual-app/core declarations so desktop-electron (which includes typings/window.ts) can build
diff --git a/lage.config.js b/lage.config.js
index 40114b512a..a14ac13d38 100644
--- a/lage.config.js
+++ b/lage.config.js
@@ -25,6 +25,14 @@ module.exports = {
         outputGlob: BUILD_OUTPUT_GLOBS,
       },
     },
+    // Not cached: the script stages files into public/ and build-stats/ that
+    // fall outside BUILD_OUTPUT_GLOBS, so a cache hit would skip the side
+    // effects.
+    'build:browser': {
+      type: 'npmScript',
+      dependsOn: ['^build'],
+      cache: false,
+    },
   },
   cacheOptions: {
     cacheStorageConfig: {
diff --git a/package.json b/package.json
index aecdf954b9..83d7920807 100644
--- a/package.json
+++ b/package.json
@@ -24,18 +24,16 @@
     "start:server-dev": "NODE_ENV=development BROWSER_OPEN=localhost:5006 yarn npm-run-all --parallel 'start:server-monitor' 'start'",
     "start:desktop": "yarn desktop-dependencies && npm-run-all --parallel 'start:desktop-*'",
     "start:docs": "yarn workspace docs start",
-    "desktop-dependencies": "npm-run-all --parallel rebuild-electron build:browser-backend build:plugins-service",
+    "desktop-dependencies": "npm-run-all --parallel rebuild-electron build:plugins-service",
     "start:desktop-node": "yarn workspace @actual-app/core watch:node",
     "start:desktop-client": "yarn workspace @actual-app/web watch",
     "start:desktop-server-client": "yarn workspace @actual-app/web build:browser",
     "start:desktop-electron": "yarn workspace desktop-electron watch",
-    "start:browser": "yarn workspace plugins-service build-dev && npm-run-all --parallel 'start:browser-*'",
+    "start:browser": "npm-run-all --parallel 'start:browser-*' 'start:service-plugins'",
     "start:service-plugins": "yarn workspace plugins-service watch",
-    "start:browser-backend": "yarn workspace @actual-app/core watch:browser",
     "start:browser-frontend": "yarn workspace @actual-app/web start:browser",
     "start:storybook": "yarn workspace @actual-app/components start:storybook",
     "build": "lage build",
-    "build:browser-backend": "yarn workspace @actual-app/core build:browser",
     "build:server": "yarn build:browser && yarn workspace @actual-app/sync-server build",
     "build:browser": "./bin/package-browser",
     "build:desktop": "./bin/package-electron",
diff --git a/packages/desktop-client/.gitignore b/packages/desktop-client/.gitignore
index 7bc018d77e..49a135ca82 100644
--- a/packages/desktop-client/.gitignore
+++ b/packages/desktop-client/.gitignore
@@ -8,6 +8,7 @@ coverage
 test-results
 playwright-report
 blob-report
+.playwright-cli
 
 # production
 build
diff --git a/packages/desktop-client/bin/build-browser b/packages/desktop-client/bin/build-browser
deleted file mode 100755
index 0b5a283cfb..0000000000
--- a/packages/desktop-client/bin/build-browser
+++ /dev/null
@@ -1,17 +0,0 @@
-#!/bin/sh -ex
-
-ROOT=`dirname $0`
-cd "$ROOT/.."
-
-echo "Building the browser..."
-
-rm -fr build
-
-export REACT_APP_BACKEND_WORKER_HASH=`ls "$ROOT"/../public/kcab/kcab.worker.*.js |  sed 's/.*kcab\.worker\.\(.*\)\.js/\1/'`
-
-yarn build --mode=browser
-
-rm -fr build-stats
-mkdir build-stats
-mv build/kcab/stats.json build-stats/loot-core-stats.json
-mv ./stats.json build-stats/web-stats.json
diff --git a/packages/desktop-client/package.json b/packages/desktop-client/package.json
index 82ba95415e..ce4fb1d62a 100644
--- a/packages/desktop-client/package.json
+++ b/packages/desktop-client/package.json
@@ -104,7 +104,7 @@
     "start:browser": "cross-env ./bin/watch-browser",
     "watch": "cross-env BROWSER=none yarn start",
     "build": "vite build",
-    "build:browser": "cross-env ./bin/build-browser",
+    "build:browser": "vite build --mode=browser",
     "generate:i18n": "i18next",
     "test": "vitest --run",
     "validate:theme-catalog": "node --experimental-strip-types bin/validate-theme-catalog.mts",
@@ -164,6 +164,7 @@
     "mdast-util-newline-to-break": "^2.0.0",
     "memoize-one": "^6.0.0",
     "pikaday": "1.8.2",
+    "plugins-service": "workspace:*",
     "promise-retry": "^2.0.1",
     "re-resizable": "^6.11.2",
     "react": "19.2.4",
diff --git a/packages/desktop-client/tsconfig.json b/packages/desktop-client/tsconfig.json
index eda13c79d2..9285906bae 100644
--- a/packages/desktop-client/tsconfig.json
+++ b/packages/desktop-client/tsconfig.json
@@ -24,6 +24,9 @@
     },
     {
       "path": "../loot-core"
+    },
+    {
+      "path": "../plugins-service"
     }
   ],
   "include": ["**/*.ts", "src/**/*.tsx", "src/**/*.js"],
diff --git a/packages/desktop-client/vite.config.mts b/packages/desktop-client/vite.config.mts
index 3fb9477818..7e1ba31654 100644
--- a/packages/desktop-client/vite.config.mts
+++ b/packages/desktop-client/vite.config.mts
@@ -1,3 +1,7 @@
+import { spawn } from 'node:child_process';
+import type { ChildProcess } from 'node:child_process';
+import { createReadStream } from 'node:fs';
+import { cp, mkdir, readdir, rename, rm, writeFile } from 'node:fs/promises';
 import * as path from 'path';
 import { fileURLToPath } from 'url';
 
@@ -8,7 +12,7 @@ import react, { reactCompilerPreset } from '@vitejs/plugin-react';
 import type { PreRenderedAsset } from 'rolldown';
 import { visualizer } from 'rollup-plugin-visualizer';
 /// <reference types="vitest" />
-import { defineConfig, loadEnv } from 'vite';
+import { build, defineConfig, loadEnv } from 'vite';
 import type { Plugin } from 'vite';
 import { VitePWA } from 'vite-plugin-pwa';
 
@@ -103,7 +107,163 @@ const injectShims = (): Plugin[] => {
 
 // https://vitejs.dev/config/
 
-export default defineConfig(async ({ mode }) => {
+const lootCoreRoot = path.resolve(__dirname, '../loot-core');
+const lootCoreOutDir = path.resolve(lootCoreRoot, 'lib-dist/browser');
+const lootCoreConfig = path.resolve(lootCoreRoot, 'vite.config.mts');
+const sqlWasmSrc = path.resolve(
+  __dirname,
+  '../../node_modules/@jlongster/sql.js/dist/sql-wasm.wasm',
+);
+const publicDir = path.resolve(__dirname, 'public');
+const publicDataDir = path.resolve(publicDir, 'data');
+const publicKcabDir = path.resolve(publicDir, 'kcab');
+const buildStatsDir = path.resolve(__dirname, 'build-stats');
+const pluginsServiceDistDir = path.resolve(
+  __dirname,
+  '../plugins-service/dist',
+);
+const serviceWorkerDir = path.resolve(__dirname, 'service-worker');
+
+const WORKER_FILENAME_RE = /^kcab\.worker\.(.+)\.js$/;
+
+async function extractWorkerHash(): Promise<string> {
+  const files = await readdir(lootCoreOutDir);
+  for (const f of files) {
+    const match = f.match(WORKER_FILENAME_RE);
+    if (match) return match[1];
+  }
+  throw new Error(
+    `loot-core worker build produced no hashed output at ${lootCoreOutDir}`,
+  );
+}
+
+// Serve loot-core worker assets with correct content types so the browser can
+// stream-compile the sql.js wasm module.
+const CONTENT_TYPES: Record<string, string> = {
+  '.js': 'application/javascript',
+  '.mjs': 'application/javascript',
+  '.map': 'application/json',
+  '.wasm': 'application/wasm',
+};
+
+async function stagePluginsService(): Promise<void> {
+  await rm(serviceWorkerDir, { recursive: true, force: true });
+  await cp(pluginsServiceDistDir, serviceWorkerDir, { recursive: true });
+}
+
+async function stagePublicData(): Promise<void> {
+  const migrationsDest = path.resolve(publicDataDir, 'migrations');
+  await mkdir(publicDataDir, { recursive: true });
+  await rm(migrationsDest, { recursive: true, force: true });
+  await Promise.all([
+    cp(path.resolve(lootCoreRoot, 'migrations'), migrationsDest, {
+      recursive: true,
+    }),
+    cp(
+      path.resolve(lootCoreRoot, 'default-db.sqlite'),
+      path.resolve(publicDataDir, 'default-db.sqlite'),
+    ),
+    cp(sqlWasmSrc, path.resolve(publicDir, 'sql-wasm.wasm')),
+  ]);
+
+  const entries = await readdir(publicDataDir, {
+    recursive: true,
+    withFileTypes: true,
+  });
+  const files = entries
+    .filter(e => e.isFile())
+    .map(e =>
+      path
+        .relative(publicDataDir, path.join(e.parentPath, e.name))
+        .replaceAll(path.sep, '/'),
+    )
+    .sort();
+  await writeFile(
+    path.resolve(publicDir, 'data-file-index.txt'),
+    files.join('\n') + '\n',
+  );
+}
+
+const lootCoreBackend = (): Plugin => ({
+  name: 'loot-core-backend',
+  configureServer(server) {
+    const child: ChildProcess = spawn(
+      'yarn',
+      [
+        'vite',
+        'build',
+        '--config',
+        lootCoreConfig,
+        '--mode',
+        'development',
+        '--watch',
+      ],
+      { cwd: lootCoreRoot, stdio: 'inherit' },
+    );
+    child.on('error', err => {
+      server.config.logger.error(
+        `loot-core backend failed to spawn: ${err.message}`,
+      );
+    });
+    const cleanup = () => {
+      if (!child.killed) child.kill('SIGTERM');
+    };
+    server.httpServer?.once('close', cleanup);
+    process.once('SIGINT', cleanup);
+    process.once('SIGTERM', cleanup);
+    process.once('exit', cleanup);
+
+    server.middlewares.use('/kcab', (req, res, next) => {
+      const url = new URL(req.url ?? '/', 'http://localhost');
+      const filePath = path.join(lootCoreOutDir, url.pathname);
+      if (!filePath.startsWith(lootCoreOutDir + path.sep)) return next();
+      const stream = createReadStream(filePath);
+      stream
+        .on('open', () => {
+          res.setHeader(
+            'Content-Type',
+            CONTENT_TYPES[path.extname(filePath)] ?? 'application/octet-stream',
+          );
+          stream.pipe(res);
+        })
+        .on('error', () => next());
+    });
+  },
+  async closeBundle() {
+    await mkdir(buildStatsDir, { recursive: true });
+    try {
+      await rename(
+        path.resolve(__dirname, 'build/kcab/stats.json'),
+        path.resolve(buildStatsDir, 'loot-core-stats.json'),
+      );
+    } catch (err) {
+      if ((err as NodeJS.ErrnoException).code !== 'ENOENT') throw err;
+    }
+  },
+});
+
+const pluginsServiceAssets = (): Plugin => ({
+  name: 'plugins-service-assets',
+  configureServer(server) {
+    server.middlewares.use('/service-worker', (req, res, next) => {
+      const url = new URL(req.url ?? '/', 'http://localhost');
+      const filePath = path.join(pluginsServiceDistDir, url.pathname);
+      if (!filePath.startsWith(pluginsServiceDistDir + path.sep)) return next();
+      const stream = createReadStream(filePath);
+      stream
+        .on('open', () => {
+          res.setHeader(
+            'Content-Type',
+            CONTENT_TYPES[path.extname(filePath)] ?? 'application/octet-stream',
+          );
+          stream.pipe(res);
+        })
+        .on('error', () => next());
+    });
+  },
+});
+
+export default defineConfig(async ({ mode, command }) => {
   const env = loadEnv(mode, process.cwd(), '');
   const devHeaders = {
     'Cross-Origin-Opener-Policy': 'same-origin',
@@ -116,6 +276,32 @@ export default defineConfig(async ({ mode }) => {
     process.env.REACT_APP_BRANCH = process.env.BRANCH;
   }
 
+  // Electron packaging (--mode=desktop) bundles loot-core directly, so skip
+  // all browser-only staging there.
+  if (mode !== 'desktop') {
+    if (command === 'build') {
+      const stageKcab = build({
+        configFile: lootCoreConfig,
+        mode: 'production',
+        root: lootCoreRoot,
+      }).then(async () => {
+        const hash = await extractWorkerHash();
+        await rm(publicKcabDir, { recursive: true, force: true });
+        await cp(lootCoreOutDir, publicKcabDir, { recursive: true });
+        return hash;
+      });
+      const [, , hash] = await Promise.all([
+        stagePublicData(),
+        stagePluginsService(),
+        stageKcab,
+      ]);
+      process.env.REACT_APP_BACKEND_WORKER_HASH = hash;
+    } else {
+      await stagePublicData();
+      process.env.REACT_APP_BACKEND_WORKER_HASH = 'dev';
+    }
+  }
+
   const browserOpen = env.BROWSER_OPEN ? `//${env.BROWSER_OPEN}` : true;
 
   return {
@@ -213,13 +399,18 @@ export default defineConfig(async ({ mode }) => {
           }),
       injectShims(),
       addWatchers(),
+      mode === 'desktop' ? undefined : lootCoreBackend(),
+      mode === 'desktop' ? undefined : pluginsServiceAssets(),
       react(),
       babel({
         include: [reactCompilerInclude],
         // n.b. Must be a string to ensure plugin resolution order. See https://github.com/actualbudget/actual/pull/5853
         presets: [reactCompilerPreset()],
       }),
-      visualizer({ template: 'raw-data' }),
+      visualizer({
+        template: 'raw-data',
+        filename: 'build-stats/web-stats.json',
+      }),
       !!env.HTTPS && basicSsl(),
     ],
     test: {
diff --git a/packages/loot-core/bin/build-browser b/packages/loot-core/bin/build-browser
deleted file mode 100755
index 8758b7fdee..0000000000
--- a/packages/loot-core/bin/build-browser
+++ /dev/null
@@ -1,40 +0,0 @@
-#!/bin/bash -e
-
-cd `dirname "$0"`
-ROOT=`pwd -P`
-VITE_ARGS=""
-
-PUBLIC_DIR="$ROOT"/../../desktop-client/public
-DATA_DIR="$PUBLIC_DIR"/data
-mkdir -p "$DATA_DIR"
-"$ROOT"/copy-migrations "$DATA_DIR"
-
-cd "$DATA_DIR"
-find * -type f | sort > ../data-file-index.txt
-cd "$ROOT"
-
-# Clean out previous build files
-rm -f ../lib-dist/browser/*
-rm -rf ../../desktop-client/public/kcab
-
-if [ $NODE_ENV == 'development' ]; then
-  # In dev mode, always enable watch mode and symlink the build files.
-  # Make sure to do this before starting the build since watch mode
-  # will block
-  VITE_ARGS="$VITE_ARGS --watch"
-  if [ "$OSTYPE" == "msys" ]; then
-    # Ensure symlinks are created as native Windows symlinks.
-    export MSYS=winsymlinks:nativestrict
-  fi
-  ln -snf "$ROOT"/../lib-dist/browser ../../desktop-client/public/kcab
-fi
-
-cp ../../../node_modules/@jlongster/sql.js/dist/sql-wasm.wasm "$PUBLIC_DIR"/sql-wasm.wasm
-
-yarn vite build --config ../vite.config.mts --mode $NODE_ENV $VITE_ARGS
-
-if [ $NODE_ENV == 'production' ]; then
-  # In production, just copy the built files
-  mkdir ../../desktop-client/public/kcab
-  cp -r ../lib-dist/browser/* ../../desktop-client/public/kcab
-fi
diff --git a/packages/loot-core/bin/copy-migrations b/packages/loot-core/bin/copy-migrations
deleted file mode 100755
index d029d25549..0000000000
--- a/packages/loot-core/bin/copy-migrations
+++ /dev/null
@@ -1,9 +0,0 @@
-#!/bin/bash -e
-
-ROOT=`dirname $(dirname "$0")`
-DEST="$1"
-
-rm -rf "$DEST"/migrations
-mkdir -p "$DEST"/migrations
-cp "$ROOT"/migrations/* "$DEST"/migrations/
-cp "$ROOT"/default-db.sqlite "$DEST"
diff --git a/packages/loot-core/package.json b/packages/loot-core/package.json
index 3d9e50cb04..3499988afe 100644
--- a/packages/loot-core/package.json
+++ b/packages/loot-core/package.json
@@ -158,8 +158,6 @@
   "scripts": {
     "build:node": "cross-env NODE_ENV=production vite build --config ./vite.desktop.config.mts",
     "watch:node": "cross-env NODE_ENV=development vite build --config ./vite.desktop.config.mts --watch",
-    "build:browser": "cross-env NODE_ENV=production ./bin/build-browser",
-    "watch:browser": "cross-env NODE_ENV=development ./bin/build-browser",
     "generate:i18n": "i18next",
     "test": "npm-run-all -cp 'test:*'",
     "test:node": "ENV=node vitest --run",
diff --git a/packages/plugins-service/bin/build-service-worker b/packages/plugins-service/bin/build-service-worker
deleted file mode 100755
index 8f378fc98a..0000000000
--- a/packages/plugins-service/bin/build-service-worker
+++ /dev/null
@@ -1,28 +0,0 @@
-#!/bin/bash -e
-
-cd `dirname "$0"`
-ROOT=`pwd -P`
-VITE_ARGS=""
-
-DESKTOP_DIR="$ROOT"/../../desktop-client
-SERVICE_WORKER_DIR="$DESKTOP_DIR"/service-worker
-
-# Clean out previous build files
-rm -f ../dist/*
-rm -rf "$DESKTOP_DIR"/service-worker
-
-if [ $NODE_ENV == 'development' ]; then
-  if [ "$OSTYPE" == "msys" ]; then
-    # Ensure symlinks are created as native Windows symlinks.
-    export MSYS=winsymlinks:nativestrict
-  fi
-  ln -snf "$ROOT"/../dist/ "$DESKTOP_DIR"/service-worker
-fi
-
-yarn vite build --config ../vite.config.mts --mode $NODE_ENV $VITE_ARGS
-
-if [ $NODE_ENV == 'production' ]; then
-  # In production, just copy the built files
-  mkdir -p "$SERVICE_WORKER_DIR"
-  cp -r ../dist/* "$DESKTOP_DIR"/service-worker
-fi
\ No newline at end of file
diff --git a/packages/plugins-service/package.json b/packages/plugins-service/package.json
index a456806815..d4db1e73d8 100644
--- a/packages/plugins-service/package.json
+++ b/packages/plugins-service/package.json
@@ -6,9 +6,9 @@
   "author": "",
   "main": "plugin-sw.js",
   "scripts": {
-    "build": "cross-env NODE_ENV=production ./bin/build-service-worker",
-    "build-dev": "cross-env NODE_ENV=development ./bin/build-service-worker",
-    "watch": "cross-env NODE_ENV=development ./bin/build-service-worker --watch",
+    "build": "cross-env NODE_ENV=production vite build",
+    "build-dev": "cross-env NODE_ENV=development vite build",
+    "watch": "cross-env NODE_ENV=development vite build --watch",
     "typecheck": "tsgo -b && tsc-strict"
   },
   "dependencies": {
diff --git a/upcoming-release-notes/7602.md b/upcoming-release-notes/7602.md
new file mode 100644
index 0000000000..dc551a5878
--- /dev/null
+++ b/upcoming-release-notes/7602.md
@@ -0,0 +1,6 @@
+---
+category: Maintenance
+authors: [MatissJanis]
+---
+
+Build scripts: port browser build version to using lage
diff --git a/yarn.lock b/yarn.lock
index 7626783485..cee3bed87a 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -264,6 +264,7 @@ __metadata:
     mdast-util-newline-to-break: "npm:^2.0.0"
     memoize-one: "npm:^6.0.0"
     pikaday: "npm:1.8.2"
+    plugins-service: "workspace:*"
     promise-retry: "npm:^2.0.1"
     re-resizable: "npm:^6.11.2"
     react: "npm:19.2.4"
@@ -22776,7 +22777,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"plugins-service@workspace:packages/plugins-service":
+"plugins-service@workspace:*, plugins-service@workspace:packages/plugins-service":
   version: 0.0.0-use.local
   resolution: "plugins-service@workspace:packages/plugins-service"
   dependencies: