# Backend Stack

> **Node.js, NestJS, REST APIs, Database, Security, Design Patterns, Microservices, GraphQL** — shared by both the [indian-sde-faang lane](../lanes/indian-sde-faang/INDEX.md) and the [abroad-full-stack lane](../lanes/abroad-full-stack/INDEX.md).

| Section | Files | Topics |
|---------|------:|--------|
| [Node.js](nodejs/INDEX.md) | 11 | Event loop, streams, clustering, web streams, child processes, test runner |
| [NestJS](nestjs/INDEX.md) | 14 | Modules, DI, guards, pipes, interceptors, CQRS, microservices |
| [REST APIs](rest-api/INDEX.md) | 13 | HTTP methods, status codes, versioning, pagination, auth, OpenAPI, caching |
| [Database](database/INDEX.md) | 14 | PostgreSQL, indexes, transactions, MVCC, Prisma, query planning, migrations |
| [Security](security/INDEX.md) | 13 | JWT, OAuth, XSS, CSRF, RBAC, threat modeling, secrets management |
| [Design-Patterns](design-patterns/INDEX.md) | 15 | Singleton, Factory, Strategy, Repository, CQRS, Module, State |
| [Microservices](microservices/INDEX.md) | 14 | Service discovery, saga, circuit breaker, event sourcing, gRPC, service mesh |
| [GraphQL](graphql/INDEX.md) | 8 | Schema design, queries/mutations, Apollo Server, performance, security |

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**Lane-specific overlays:** Add interview strategy context, behavioral stories, and prep plans in [Interview Lanes](../lanes/INDEX.md) — the stacks stay stack-pure.