List all Dynamic APIs.

0-2 years experience

1. 1You need to add a new API endpoint that accepts a user ID in the URL, like /api/users/[id]. How would you create the file structure in a Next.js project to make this work?
2. 2If you run the dev server and navigate to /api/products/123, which file does Next.js try to load, and what happens if that file doesn't exist?
3. 3Write a small Node script that prints the relative paths of all files under pages/api that contain a dynamic segment (e.g., [id].js or [...slug].js).

2-5 years experience

1. 1Your team wants to generate API documentation automatically. Explain how you would extract a list of all dynamic API routes from the codebase and what edge cases you need to handle.
2. 2During a deployment a newly added dynamic API route returns 404. Walk me through how you'd debug the routing and verify the route is correctly recognized.

5-8 years experience

1. 1In a large Next.js monorepo with hundreds of dynamic API routes, discuss the performance implications of scanning the filesystem at runtime versus at build time. Which approach would you choose and why?
2. 2How would you design a versioning strategy for dynamic API routes that need to evolve without breaking existing clients, given Next.js routing constraints?
3. 3Describe how you would enforce consistent naming and parameter validation across all dynamic API routes in a team, possibly using linting or code generation.

8+ years experience

1. 1Your organization is migrating from a legacy Express API layer to Next.js API routes. Outline a migration plan that ensures all existing dynamic endpoints are preserved and discoverable, and discuss cross‑team coordination.
2. 2When scaling to millions of requests, what architectural changes would you make to the handling of dynamic API routes in Next.js to avoid cold starts and maintain low latency?
3. 3Propose a strategy for centralizing authentication and rate limiting across hundreds of dynamic API routes while keeping the codebase maintainable.