Question 1

How do you implement feature flags in production?

Accepted Answer

Feature flags wrap new functionality in conditional checks that can be toggled without deploying new code. Implement them using a feature flag service (LaunchDarkly, Unleash, Flagsmith) or a simple config-driven approach with a database-backed toggle. The flag evaluation runs server-side on each request, enabling gradual rollouts, A/B tests, and instant kill switches.

Question 2

How do you structure environment variables in a full-stack app?

Accepted Answer

Use a `.env` file per environment (`.env.local`, `.env.production`) with a `.env.example` checked into version control documenting every required variable. Prefix client-exposed variables (`NEXT_PUBLIC_`, `VITE_`) to distinguish them from server-only secrets. Load variables through your framework's built-in env handling and validate them at startup with a schema (zod, envalid).

Question 3

What is a database migration and how should you manage them?

Accepted Answer

A database migration is a versioned, incremental change to your database schema (adding tables, columns, indexes) tracked in code alongside your application. Migrations run in order during deployment to keep the database in sync with application code. Use a migration tool (Prisma Migrate, Drizzle Kit, Flyway, Alembic) that generates timestamped migration files and tracks which have been applied.

Question 4

What is a monorepo and when should you use one?

Accepted Answer

A monorepo is a single repository that contains multiple projects, packages, or services. Instead of separate repos for your frontend, backend, and shared libraries, everything lives together with shared tooling and dependencies. Tools like Turborepo, Nx, and pnpm workspaces make monorepos practical at scale. Use one when your projects share code, need coordinated releases, or when context-switching between repos creates friction.

Question 5

What is edge computing in web development?

Accepted Answer

Edge computing in web development runs server-side code on CDN nodes geographically close to the user instead of a single origin server. Platforms like Cloudflare Workers, Vercel Edge Functions, and Deno Deploy execute lightweight functions at 200+ global locations. This reduces latency to under 50ms for most users and enables per-request personalization without the cold starts of traditional serverless.

Question 6

What is the difference between monorepo and polyrepo?

Accepted Answer

A monorepo stores all projects and services in a single version-controlled repository. A polyrepo gives each project its own separate repository. Monorepos simplify cross-project changes and dependency management but require specialized tooling (Nx, Turborepo) at scale; polyrepos offer clearer ownership boundaries and simpler CI but make coordinated changes across services harder.