APIs are contracts. Test them like it.
Every microservice, every third-party integration, every mobile-to- backend call — it's a contract between two systems. When that contract quietly breaks, your users find it before you do. API tests are what stop that from happening.
The four layers of API testing we cover
Contract Testing
Pact, Spring Cloud Contract, or OpenAPI-driven. Consumer and provider verified in CI.
Functional Testing
Happy paths, error paths, edge cases. REST-Assured, Karate, or Playwright API mode.
Security Testing
Authentication, authorization, input validation, OWASP API Top 10 coverage.
Load Testing
k6, Gatling, or JMeter. Realistic traffic models, not just constant RPS.
Tools we're fluent in
- REST-Assured — Java-first, best-in-class for JVM stacks
- Karate — DSL-driven, great for teams without deep programming experience
- Playwright API — one tool for UI + API, growing fast
- Postman + Newman — for teams already invested in Postman collections
- Pact — contract testing for microservice architectures
- k6 — our default for API load and performance tests
Typical engagement
- API surface audit — inventory of endpoints, current coverage, schemas
- Framework pilot — 2 weeks, 20–30 core endpoint tests running in CI
- Full build-out — grow coverage, add contract tests for external consumers
- Load-test baseline — so you have numbers to compare against later
Related
Often paired with QA automation for full E2E coverage, and performance testing when load work grows past a few endpoints.