https://learn-nestjs.com/ Free NestJS tutorials, plus how NestJS conventions make agent-generated backend code reviewable. Sun, 06 Sep 2026 03:07:12 GMT https://learn-nestjs.com/hello-world/https://learn-nestjs.com/hello-world/A running NestJS application in three commands, and what each generated file is actually for. https://learn-nestjs.com/ai/conventions-for-agents/https://learn-nestjs.com/ai/conventions-for-agents/The framework's opinionated structure turns out to be exactly what makes generated back-end code fast to review. Here is how to lean on it. https://learn-nestjs.com/review/failure-modes/https://learn-nestjs.com/review/failure-modes/TypeScript catches the type errors. What gets through is authorisation, validation configuration, and logic drifting out of services — and those are the ones that matter. https://learn-nestjs.com/review/dependencies/https://learn-nestjs.com/review/dependencies/npm's problems, plus a framework whose packages must all be on the same major version, plus a decorator ecosystem where a version mismatch produces a runtime error with no useful message. https://learn-nestjs.com/modules/https://learn-nestjs.com/modules/The unit of organisation in Nest, and the thing that decides what can see what. https://learn-nestjs.com/ai/agents-md/https://learn-nestjs.com/ai/agents-md/Nest already decides where things go, so this file has one real job: the security configuration the framework will happily let you get wrong. https://learn-nestjs.com/controllers/https://learn-nestjs.com/controllers/Parse the request, call a service, return a value. Everything else in a controller is a mistake. https://learn-nestjs.com/ai/tokenomics/https://learn-nestjs.com/ai/tokenomics/Nest's interceptors and guards are exactly the right shape for cost control: measure in one place, enforce before the handler runs, and no feature can be added without both. https://learn-nestjs.com/review/security/https://learn-nestjs.com/review/security/The framework gives you the right places to put security controls. What it will not do is tell you when one is missing — and a missing global is invisible until someone finds it. https://learn-nestjs.com/providers-and-di/https://learn-nestjs.com/providers-and-di/How Nest constructs your objects, and the injection patterns worth knowing beyond the constructor. https://learn-nestjs.com/review/performance/https://learn-nestjs.com/review/performance/Two Nest-specific problems dominate: N+1 queries through the ORM, and request-scoped providers that quietly make your entire dependency graph rebuild on every request. https://learn-nestjs.com/dto-and-validation/https://learn-nestjs.com/dto-and-validation/The boundary where untrusted input becomes a typed object. Get this right and most of your input-handling bugs disappear. https://learn-nestjs.com/guards-and-auth/https://learn-nestjs.com/guards-and-auth/Guards answer one question: may this request proceed? Getting the difference between authentication and authorisation right is where most back-end vulnerabilities live. https://learn-nestjs.com/database-and-testing/https://learn-nestjs.com/database-and-testing/Wiring a database into a Nest module, and building the test setup that lets an agent iterate without a container. https://learn-nestjs.com/interceptors/https://learn-nestjs.com/interceptors/Code that wraps a handler — before and after. Logging, response shaping, caching, timeouts and cleanup all live here. https://learn-nestjs.com/exception-filters/https://learn-nestjs.com/exception-filters/Turning thrown errors into HTTP responses — in one place, with full detail in the log and none of it leaking to the client. https://learn-nestjs.com/middleware-and-lifecycle/https://learn-nestjs.com/middleware-and-lifecycle/The layer beneath Nest's abstractions, and the module hooks that decide whether your redeploys leak database connections. https://learn-nestjs.com/configuration/https://learn-nestjs.com/configuration/An application that refuses to start on a missing secret is far better than one that starts and fails on the first request that needs it.