API testing’s the backbone, ensuring the flow, Validate the data, see if the system will grow. Functional checks, we’re testing the core, Make sure each request delivers, and nothing’s a bore. Boundary tests hit the limits, handle extremes, Push the API to its edges, make sure it screams. Security tests, inject with intent, Break the system, prove it’s resilient and bent. Performance testing—how fast can it fly? Under load and stress, make the response never die. Unit tests check if the parts stand tall, Integration ensures all components play ball. Mock the backend, test with precision, Check each interaction, ensure no division. Error handling’s key—can the API stand, When things go wrong, can it still take command? Versioning’s important, maintain backwards pace, Older clients need support, no errors in the race. Data consistency—ensure that it’s true, From request to response, it’s all gotta go through. Load balancing, we need that perfect scale, When traffic comes knocking, can the system prevail? Cross-platform works, with every OS call, Test compatibility so nothing will fall. Cross-database checks, make sure the link’s fine, Populate references, keep data in line. Automation scripts, they run without fail, CI/CD ensures no bugs derail.