NestJS Professional Standards & Competencies 5

Question 1

What professional practice should NestJS developers follow when exposing sensitive configuration such as JWT secrets?

Accepted Answer

Load secrets from environment variables or a secrets manager and never commit them to version control

Answer

Secrets must be externalized via environment variables or vaults to prevent exposure through version control or logs.

Question 2

A NestJS team wants to enforce coding standards automatically. Which tooling combination is considered a professional standard?

Accepted Answer

ESLint with @typescript-eslint rules, Prettier for formatting, and pre-commit hooks via Husky

Answer

Automated linting, formatting, and pre-commit hooks enforce standards consistently without relying on human memory.

Question 3

When building a NestJS API that will be consumed by mobile clients on unreliable networks, which response design practice improves resilience?

Accepted Answer

Support pagination, sparse fieldsets, and idempotent retry-safe endpoints

Answer

Pagination limits payload size, sparse fieldsets reduce bandwidth, and idempotent endpoints allow safe client retries on network failure.

Question 4

What does professional API versioning look like in a NestJS REST application?

Accepted Answer

Use URI versioning (/v1/), header versioning, or media type versioning consistently across the codebase

Answer

NestJS has built-in versioning support; choosing a consistent strategy prevents consumer confusion and allows parallel version support.

Question 5

A NestJS service makes external HTTP calls. What professional pattern prevents cascading failures when the downstream service is slow?

Accepted Answer

Implement a circuit breaker pattern with timeout and fallback using a library like Cockatiel or Nest's HttpModule with timeout

Answer

Circuit breakers halt calls to failing services and return fallbacks, preventing slow dependencies from exhausting the calling service's resources.

NestJS Practice Test