The role Next.js plays
Next.js commonly controls routing, server components, API routes, actions, caching, and deployment. Its surrounding reliability depends on version-specific APIs, client directives, hydration, route conventions, and runtime choices, so the visible error may originate outside the file the AI last changed.
Specific failure patterns to inspect
For AI App Won’t Deploy, common causes include dependency conflicts, case-sensitive imports, unsupported runtime APIs, missing production variables. Generated implementations also tend to omit defensive error handling, version checks, idempotency, or a safe difference between public configuration and private credentials.
A safer diagnostic sequence
Preserve the current branch and exact error. Then save the complete build log; compare runtime versions; list required environment-variable names. Follow one test request across the interface, server or provider, and durable data rather than making several speculative code changes.
Repair boundaries
The repair should change the narrowest contract that is actually broken. Broader refactoring is justified only when duplicated ownership or an unsafe architecture would otherwise let the failure return.
What to avoid
Do not randomly upgrade every package or expose secret values in screenshots. Do not upgrade the entire Next.js stack during a contained incident unless version incompatibility is the proven cause.
What a complete handoff includes
The handoff identifies the root cause, affected code or settings, safe test case, deployment note, and any remaining follow-up. The repaired behavior should be protected by a repeatable check.