diff --git a/scripts/check-packaged-runtime.js b/scripts/check-packaged-runtime.js
index 76ea57d..68b441f 100644
--- a/scripts/check-packaged-runtime.js
+++ b/scripts/check-packaged-runtime.js
@@ -73,6 +73,7 @@ function run(command, args, options = {}) {
     env: options.env || process.env,
     encoding: 'utf8',
     stdio: ['ignore', 'pipe', 'pipe'],
+    ...(options.maxBuffer ? { maxBuffer: options.maxBuffer } : {}),
   });
   if (result.error || result.status !== 0) {
     fail(`${command} ${args.join(' ')} failed: ${(result.error?.message || result.stderr || result.stdout || '').trim()}`);
@@ -231,7 +232,10 @@ function inspectPackage(appPath) {
     fail(`Python version ${versionOutput} does not match manifest ${normalized.python.version}`);
   }
   run(pythonPath, ['-c', [
-    'import fastapi, uvicorn, pydantic, requests, torch, whisper',
+    'import fastapi, uvicorn, pydantic, requests, numpy as np, torch, whisper',
+    'a = np.ones((32, 32)); b = a @ a; assert float(b[0, 0]) == 32.0',
+    'from numba import njit; f = njit(lambda x: x + 1); assert f(2) == 3',
+    'x = torch.tensor([1.0, 2.0]); y = x * 2; assert y.tolist() == [2.0, 4.0]',
     'from importlib.metadata import version, distributions; assert version("openai-whisper") == "20250625"',
     'import main, sys; forbidden = ("whisperx", "nemo", "pyannote.audio", "df", "mediapipe", "cv2", "openai", "anthropic", "moviepy"); assert all(name not in sys.modules for name in forbidden)',
     'installed = {(d.metadata.get("Name") or "").lower() for d in distributions()}; assert not installed.intersection({"whisperx", "nemo-toolkit", "pyannote.audio", "deepfilternet", "mediapipe", "opencv-python", "openai", "anthropic", "moviepy"})',
@@ -241,6 +245,20 @@ function inspectPackage(appPath) {
   if (!/arm64/i.test(architecture)) fail(`bundled Python architecture is not arm64: ${architecture.trim()}`);
   const forbidden = findForbiddenResourceEntry(resourcesPath);
   if (forbidden) fail(`packaged Resources contains forbidden developer/cache data: ${forbidden}`);
+  for (const relativePath of [
+    'llvmlite/binding/libllvmlite.dylib',
+    'numpy/.dylibs/libopenblas64_.0.dylib',
+    'torch/lib/libtorch_cpu.dylib',
+    'torch/lib/libtorch_python.dylib',
+  ]) {
+    const nativePath = path.join(corePackRoot, ...relativePath.split('/'));
+    if (!fs.existsSync(nativePath)) fail(`packaged native runtime target is missing: ${relativePath}`);
+    run('/usr/bin/codesign', ['--verify', '--strict', nativePath]);
+    const symbols = run('/usr/bin/nm', ['-m', nativePath], { maxBuffer: 16 * 1024 * 1024 }).stdout || '';
+    if (/\bnon-external\b/i.test(symbols)) {
+      fail(`packaged native runtime target still contains local symbols after strip -x: ${relativePath}`);
+    }
+  }
   for (const relativePath of [
     'include',
     'lib/python3.11/site-packages',
@@ -275,7 +293,7 @@ function inspectPackage(appPath) {
   console.log(`Core constraints: ${constraints.source}, SHA-256 ${constraints.sha256}`);
   console.log(`Core dependency lock: ${dependencyLock.source}, SHA-256 ${dependencyLock.sha256}, requireHashes=true, buildIsolation=false`);
   console.log(`Model manifest: ${modelManifest.id}, ${modelManifest.revision}, ${modelManifest.expectedBytes} bytes`);
-  console.log('Core imports: fastapi, uvicorn, pydantic, requests, torch, whisper==20250625');
+  console.log('Core execution probe: NumPy/OpenBLAS, Numba/llvmlite, Torch, Whisper==20250625');
   console.log('Optional packages bundled: No');
   console.log('Backend import: passed');
   console.log('Model weight in Resources: No');
diff --git a/scripts/prepare-python-runtime.js b/scripts/prepare-python-runtime.js
index f005a54..3497009 100644
--- a/scripts/prepare-python-runtime.js
+++ b/scripts/prepare-python-runtime.js
@@ -59,6 +59,12 @@ const PORTABLE_RUNTIME_BUILD_ONLY_PATHS = [
   'bin/python3-config',
   'bin/python3.11-config',
 ];
+const NATIVE_RUNTIME_STRIP_TARGETS = [
+  'llvmlite/binding/libllvmlite.dylib',
+  'numpy/.dylibs/libopenblas64_.0.dylib',
+  'torch/lib/libtorch_cpu.dylib',
+  'torch/lib/libtorch_python.dylib',
+];
 
 function getOption(name) {
   const index = process.argv.indexOf(name);
@@ -272,7 +278,9 @@ function verifyCore(interpreterPath, relativeInterpreter) {
     SCRIPTCUT_RUNTIME_MANIFEST_SCHEMA: 'scriptcut.runtime.v1',
   });
   const probe = [
-    'import fastapi, uvicorn, pydantic, requests, torch, whisper',
+    'import fastapi, uvicorn, pydantic, requests, numpy as np, torch, whisper',
+    'a = np.ones((32, 32)); b = a @ a; assert float(b[0, 0]) == 32.0',
+    'from numba import njit; f = njit(lambda x: x + 1); assert f(2) == 3',
     'x = torch.tensor([1.0, 2.0]); y = x * 2; assert y.tolist() == [2.0, 4.0]',
     'from importlib.metadata import version; assert version("openai-whisper") == "20250625"',
     'import importlib.util, sys; import main; forbidden = ("whisperx", "nemo", "pyannote.audio", "df", "mediapipe", "cv2", "openai", "anthropic", "moviepy"); assert all(name not in sys.modules for name in forbidden)',
@@ -445,6 +453,28 @@ function prunePortableRuntimeBuildTooling() {
   return removed;
 }
 
+function stripNativeRuntimeSymbols() {
+  const optimized = { files: 0, bytesBefore: 0, bytesAfter: 0 };
+  for (const relativePath of NATIVE_RUNTIME_STRIP_TARGETS) {
+    const filePath = path.join(corePackRoot, ...relativePath.split('/'));
+    if (!fs.existsSync(filePath) || !fs.statSync(filePath).isFile()) {
+      fail(`expected native strip target is missing: ${relativePath}`);
+    }
+    const before = fs.statSync(filePath).size;
+    run('/usr/bin/strip', ['-x', filePath]);
+    // strip invalidates the wheel's Mach-O signature. Restore an ad-hoc staging
+    // signature so local probes can load it; electron-builder signs it again.
+    run('/usr/bin/codesign', ['--force', '--sign', '-', filePath]);
+    run('/usr/bin/codesign', ['--verify', '--strict', filePath]);
+    const after = fs.statSync(filePath).size;
+    if (after >= before) fail(`native symbol stripping did not reduce ${relativePath}: ${before} -> ${after}`);
+    optimized.files += 1;
+    optimized.bytesBefore += before;
+    optimized.bytesAfter += after;
+  }
+  return optimized;
+}
+
 async function main() {
   verifyTarget();
   fs.mkdirSync(buildRoot, { recursive: true });
@@ -460,10 +490,12 @@ async function main() {
   const headersRemoved = pruneNonRuntimeCoreArtifacts();
   const testsRemoved = prunePackageTestArtifacts(corePackRoot);
   const portableBuildToolingRemoved = prunePortableRuntimeBuildTooling();
+  const nativeSymbols = stripNativeRuntimeSymbols();
   const coreAfter = directoryStats(corePackRoot);
   console.log(`Torch headers removed: ${headersRemoved.files}`);
   console.log(`Package test artifacts removed: ${testsRemoved.directories} directories, ${testsRemoved.files} files, ${testsRemoved.bytes} bytes`);
   console.log(`Portable Python build-only tooling removed: ${portableBuildToolingRemoved.paths} paths, ${portableBuildToolingRemoved.files} files, ${portableBuildToolingRemoved.bytes} bytes`);
+  console.log(`Native runtime symbols stripped: ${nativeSymbols.files} files, ${nativeSymbols.bytesBefore - nativeSymbols.bytesAfter} bytes removed`);
   console.log(`Core pack files after pruning: ${coreAfter.files}`);
   console.log(`Core pack bytes after pruning: ${coreAfter.bytes}`);
   verifyCore(interpreterPath, relativeInterpreter);
diff --git a/scripts/smoke-runtime-artifacts.js b/scripts/smoke-runtime-artifacts.js
index ace151b..44f9a12 100644
--- a/scripts/smoke-runtime-artifacts.js
+++ b/scripts/smoke-runtime-artifacts.js
@@ -33,10 +33,12 @@ for (const constraint of constraintPins) {
   assert.ok(lockLines.some((line) => line.startsWith(`${normalized} --hash=sha256:`)), `core lock is missing artifact hash for: ${constraint}`);
 }
 const runtimePreparation = fs.readFileSync(path.join(__dirname, 'prepare-python-runtime.js'), 'utf8');
+const packagedRuntimeCheck = fs.readFileSync(path.join(__dirname, 'check-packaged-runtime.js'), 'utf8');
 assert.match(runtimePreparation, /function\s+pruneNonRuntimeCoreArtifacts\s*\(/);
 assert.match(runtimePreparation, /function\s+prunePythonBytecode\s*\(/);
 assert.match(runtimePreparation, /function\s+prunePackageTestArtifacts\s*\(/);
 assert.match(runtimePreparation, /function\s+prunePortableRuntimeBuildTooling\s*\(/);
+assert.match(runtimePreparation, /function\s+stripNativeRuntimeSymbols\s*\(/);
 assert.match(runtimePreparation, /profile:\s*['"]execution-only['"]/);
 assert.match(runtimePreparation, /buildToolingBundled:\s*false/);
 assert.match(runtimePreparation, /guiToolkitBundled:\s*false/);
@@ -51,6 +53,24 @@ for (const expectedBuildOnlyPath of [
 ]) {
   assert.ok(runtimePreparation.includes(`'${expectedBuildOnlyPath}'`), `portable runtime prune is missing ${expectedBuildOnlyPath}`);
 }
+for (const expectedNativeStripTarget of [
+  'llvmlite/binding/libllvmlite.dylib',
+  'numpy/.dylibs/libopenblas64_.0.dylib',
+  'torch/lib/libtorch_cpu.dylib',
+  'torch/lib/libtorch_python.dylib',
+]) {
+  assert.ok(runtimePreparation.includes(`'${expectedNativeStripTarget}'`), `native strip target is missing ${expectedNativeStripTarget}`);
+  assert.ok(packagedRuntimeCheck.includes(`'${expectedNativeStripTarget}'`), `packaged runtime verification is missing ${expectedNativeStripTarget}`);
+}
+assert.match(runtimePreparation, /['"]\/usr\/bin\/strip['"],\s*\[['"]-x['"]/);
+assert.match(runtimePreparation, /['"]\/usr\/bin\/codesign['"],\s*\[['"]--force['"],\s*['"]--sign['"],\s*['"]-['"]/);
+assert.match(runtimePreparation, /from numba import njit; f = njit/);
+assert.match(packagedRuntimeCheck, /from numba import njit; f = njit/);
+assert.match(packagedRuntimeCheck, /np\.ones\(\(32, 32\)\)/);
+assert.match(packagedRuntimeCheck, /torch\.tensor\(\[1\.0, 2\.0\]\)/);
+assert.match(packagedRuntimeCheck, /['"]\/usr\/bin\/codesign['"],\s*\[['"]--verify['"],\s*['"]--strict['"]/);
+assert.match(packagedRuntimeCheck, /['"]\/usr\/bin\/nm['"],\s*\[['"]-m['"]/);
+assert.match(packagedRuntimeCheck, /\\bnon-external\\b/);
 assert.match(runtimePreparation, /['"]--no-compile['"]/);
 assert.match(runtimePreparation, /['"]--no-build-isolation['"]/);
 assert.match(runtimePreparation, /['"]--require-hashes['"]/);