# Interview Questions — NestJS

Source: https://www.geekswithgeeks.com/en/nestjs/nestjs-interview-questions

> Common NestJS questions and solutions for technical interviews.

## Core concepts Q&A

Explain: dependency injection, how modules work, the difference between providers and services, guard vs pipe vs interceptor, how middleware fits in.

## Database & performance Q&A

Discuss: N+1 problem and solutions, lazy vs eager loading, migration strategy, caching trade-offs, query optimization.

## Architecture Q&A

How would you structure a large app? Testing strategy? Authentication & authorization? Scaling considerations?
