API Testing

Validate the whole response contract, status code, headers, body fields and types, JSON schema, response time SLA, auth behavior, safe error messages, and business rules, across both positive and negative scenarios, not just that it returned two hundred.

Define realistic journey scenarios, set up test data and a production-like environment, ramp virtual users 100 to 500 to 1000 while measuring latency percentiles and error rate, find the breaking point, diagnose and fix the bottleneck via server metrics, then re-test.

Extract the UI values, query the database as the source of truth, normalize both sides for formatting, nulls, and case, then compare and report mismatches, while handling pagination and large datasets so you compare complete, fairly formatted data.