NestJS APIs that last

I work mainly with NestJS because it gives structure without pretending the hard parts of backend work go away.

APIs that last share a few habits.

Contracts before cleverness

Name the use case. Define the request and response. Keep controllers thin. Put the real decisions in services that you can test and reason about.

If a new engineer cannot find where a rule lives in under a minute, the API is already accumulating debt.

Failure is part of the design

Timeouts, retries, validation errors, and partial failures are not edge cases — they are the product. I design for them early: clear status codes, predictable error shapes, and logs that point to a cause instead of a mystery.

Grow without rewriting

Start with a modular monolith when you can. Introduce queues, Redis, or Kafka when communication patterns demand them — not because a blog post said microservices are cool.

The goal is not to collect technologies. The goal is software that is reliable, understandable, and useful.