diff --git a/frontend/package.json b/frontend/package.json
index 211704e4ad..065309f233 100644
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -76,11 +76,19 @@
     "pretauri-build": "node scripts/build-provisioner.mjs",
     "predev": "npm run generate-icons",
     "dev": "vite",
+    "dev:core": "vite --mode core",
+    "dev:proprietary": "vite --mode proprietary",
+    "dev:saas": "vite --mode saas",
+    "dev:desktop": "vite --mode desktop",
     "prebuild": "npm run generate-icons",
     "lint": "npm run lint:eslint && npm run lint:cycles",
     "lint:eslint": "eslint --max-warnings=0",
     "lint:cycles": "dpdm src --circular --no-warning --no-tree --exit-code circular:1",
     "build": "vite build",
+    "build:core": "vite build --mode core",
+    "build:proprietary": "vite build --mode proprietary",
+    "build:saas": "vite build --mode saas",
+    "build:desktop": "vite build --mode desktop",
     "preview": "vite preview",
     "tauri-dev": "tauri dev --no-watch",
     "tauri-build": "tauri build",
@@ -92,8 +100,10 @@
     "typecheck": "npm run typecheck:proprietary",
     "typecheck:core": "tsc --noEmit --project tsconfig.core.json",
     "typecheck:proprietary": "tsc --noEmit --project tsconfig.proprietary.json",
+    "typecheck:saas": "tsc --noEmit --project tsconfig.saas.json",
     "typecheck:desktop": "tsc --noEmit --project tsconfig.desktop.json",
-    "typecheck:all": "npm run typecheck:core && npm run typecheck:proprietary && npm run typecheck:desktop",
+    "typecheck:scripts": "tsc --noEmit --project scripts/tsconfig.json",
+    "typecheck:all": "npm run typecheck:core && npm run typecheck:proprietary && npm run typecheck:saas && npm run typecheck:desktop && npm run typecheck:scripts",
     "check": "npm run typecheck && npm run lint && npm run test:run",
     "generate-licenses": "node scripts/generate-licenses.js",
     "generate-icons": "node scripts/generate-icons.js",
diff --git a/frontend/tsconfig.saas.json b/frontend/tsconfig.saas.json
new file mode 100644
index 0000000000..75e445883b
--- /dev/null
+++ b/frontend/tsconfig.saas.json
@@ -0,0 +1,20 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "paths": {
+      "@app/*": [
+        "src/saas/*",
+        "src/proprietary/*",
+        "src/core/*"
+      ],
+      "@proprietary/*": ["src/proprietary/*"],
+      "@core/*": ["src/core/*"]
+    }
+  },
+  "include": [
+    "src/*.js",
+    "src/*.ts",
+    "src/*.tsx",
+    "src/saas"
+  ]
+}
diff --git a/frontend/tsconfig.saas.vite.json b/frontend/tsconfig.saas.vite.json
new file mode 100644
index 0000000000..843368ca75
--- /dev/null
+++ b/frontend/tsconfig.saas.vite.json
@@ -0,0 +1,22 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "paths": {
+      "@app/*": [
+        "src/saas/*",
+        "src/proprietary/*",
+        "src/core/*"
+      ],
+      "@proprietary/*": ["src/proprietary/*"],
+      "@core/*": ["src/core/*"]
+    }
+  },
+  "exclude": [
+    "src/core/**/*.test.ts*",
+    "src/core/**/*.spec.ts*",
+    "src/proprietary/**/*.test.ts*",
+    "src/proprietary/**/*.spec.ts*",
+    "src/desktop",
+    "node_modules"
+  ]
+}
diff --git a/frontend/vite.config.ts b/frontend/vite.config.ts
index 02fc41a8ca..cbee5f9956 100644
--- a/frontend/vite.config.ts
+++ b/frontend/vite.config.ts
@@ -4,6 +4,16 @@ import tsconfigPaths from 'vite-tsconfig-paths';
 import { viteStaticCopy } from 'vite-plugin-static-copy';
 import path from 'path';
 
+const VALID_MODES = ['core', 'proprietary', 'saas', 'desktop'] as const;
+type BuildMode = typeof VALID_MODES[number];
+
+const TSCONFIG_MAP: Record<BuildMode, string> = {
+  core: './tsconfig.core.vite.json',
+  proprietary: './tsconfig.proprietary.vite.json',
+  saas: './tsconfig.saas.vite.json',
+  desktop: './tsconfig.desktop.vite.json',
+};
+
 export default defineConfig(({ mode }) => {
 
   // Load env file based on `mode` in the current working directory.
@@ -11,15 +21,15 @@ export default defineConfig(({ mode }) => {
   // `VITE_` prefix.
   const env = loadEnv(mode, process.cwd(), '')
 
-  // When DISABLE_ADDITIONAL_FEATURES is false (or unset), enable proprietary features
-  const isProprietary = process.env.DISABLE_ADDITIONAL_FEATURES !== 'true';
-  const isDesktopMode =
-    mode === 'desktop' ||
-    env.STIRLING_DESKTOP === 'true' ||
-    env.VITE_DESKTOP === 'true';
+  // Resolve the effective build mode.
+  // Explicit --mode flags take precedence; otherwise default to proprietary
+  // unless DISABLE_ADDITIONAL_FEATURES=true, in which case default to core.
+  const effectiveMode: BuildMode = (VALID_MODES as readonly string[]).includes(mode)
+    ? (mode as BuildMode)
+    : process.env.DISABLE_ADDITIONAL_FEATURES === 'true' ? 'core' : 'proprietary';
 
   // Validate required environment variables for desktop builds
-  if (isDesktopMode) {
+  if (effectiveMode === 'desktop') {
     const requiredEnvVars = [
       'VITE_SAAS_SERVER_URL',
       'VITE_SUPABASE_PUBLISHABLE_DEFAULT_KEY',
@@ -35,9 +45,7 @@ export default defineConfig(({ mode }) => {
     }
   }
 
-  const baseProject = isProprietary ? './tsconfig.proprietary.vite.json' : './tsconfig.core.vite.json';
-  const desktopProject = isProprietary ? './tsconfig.desktop.vite.json' : baseProject;
-  const tsconfigProject = isDesktopMode ? desktopProject : baseProject;
+  const tsconfigProject = TSCONFIG_MAP[effectiveMode];
 
   return {
     plugins: [
@@ -71,7 +79,7 @@ export default defineConfig(({ mode }) => {
         ignored: ['**/src-tauri/**'],
       },
       // Only use proxy in web mode - Tauri handles backend connections directly
-      proxy: isDesktopMode ? undefined : {
+      proxy: effectiveMode === 'desktop' ? undefined : {
         '/api': {
           target: 'http://localhost:8080',
           changeOrigin: true,