API and backend takeovers: finish the server side of your product

Backend takeovers cover the code users never see: REST or GraphQL APIs feeding a mobile app or front end, webhook receivers, scheduled jobs and queue workers. Common stacks include Node.js with Express or NestJS, Python with FastAPI or Django REST Framework, Go, Java with Spring Boot, and PHP with Laravel, usually backed by PostgreSQL or MySQL and sometimes Redis.

What inherited backends look like

There is often no OpenAPI specification, so the only description of each endpoint is the client that calls it. Database migrations may be out of step with production. Cron jobs can run on a single server nobody has logged into for months, and authentication may mix several approaches, such as API keys for partners and JWTs for the app, without consistent checks. Rate limiting and logging are frequently missing.

Information that helps

List every client that calls the API, including mobile app versions still in use, since breaking changes affect them differently. Name the hosting setup, database engine and any queues or caches. Point out endpoints that are slow or fail under load, with example requests if you have them. The repo health check gives a quick read on activity and structure when the repository is public.