This week I’ve been exploring API testing through three questions: Who consumes the API? What’s the minimum useful check for each endpoint? How much coverage do we need?
Context changes everything in API testing. An internal microservice API has different reliability requirements than a public-facing REST API used by thousands of developers. The testing strategy must match the stakes.
The Critical Questions
- Who consumes this API? Internal teams, external partners, or public developers each have different tolerance for downtime and breaking changes.
- What are the core success scenarios? Not every endpoint deserves the same level of testing rigor.
- How do users actually interact with this API? Testing isolated endpoints misses the real integration patterns.
We’re exploring a spectrum from lightweight functional tests that verify basic request/response patterns to comprehensive integration tests that simulate realistic usage flows.
The goal isn’t perfect coverage. It’s to focus testing on the reliability, performance, and behaviour that matter to the API’s users.