Vercel deployment not working? Debug build vs runtime failures
First classify the failure: build-time, startup/runtime, routing, environment configuration, or an external integration. That prevents random code changes to solve a deployment-state problem.
WHAT THIS USUALLY LOOKS LIKE
- Local development works but production fails.
- The deployment builds but a route returns 500.
- Environment-dependent integrations fail only in production.
- The deployed page is blank or assets/routes return 404.
LIKELY FAILURE AREAS
Environment variables
Production may be missing a variable, use a different value, or require a redeploy after configuration changes.
Runtime assumptions
Code can depend on filesystem, Node/browser APIs or runtime behavior that differs in the deployed environment.
Routing/build output
Framework configuration or generated output may not match the routes being requested.
CHECK THESE FIRST
- Read the build log and first runtime error rather than only the browser symptom.
- Compare production environment variables with local requirements without exposing secret values.
- Check framework/runtime versions and deployment settings.
- Inspect the failing request and function/server logs.
- Redeploy the smallest verified fix and repeat the original path.
WHAT WE NEED TO INVESTIGATE IT
- GitHub repository
- Production URL
- Vercel project/log access if the error is server-side
Do not paste passwords, private API keys or other secrets into the public submission form. We request additional access only after scope review when it is actually required.
COMMON QUESTIONS
Why can an app work locally but fail on Vercel?+
Local and deployed environments differ in variables, URLs, runtime constraints, build commands and external service configuration.
Do I need to share environment secrets?+
Do not paste secrets into the intake form. If configuration access is required for an accepted job, use the narrowest appropriate access method.
RELATED FIX GUIDES
STOP DEBUGGING
THE PROMPT LOOP.
VibeHell investigates the actual application, confirms scope and price, then implements and verifies the repair.