Developers love mocking. It’s been a go-to solution for years: Simulate external services, run tests faster, and avoid the overhead of real APIs. But here’s the truth — mocking is overused and often dangerous. It deceives you into thinking your system is stable, hiding critical failures that only appear when your code hits the real world. APIs change. Rate limits throttle you. Authentication flows break. Your tests will still pass with green colors while your app crashes in production.

Overusing mocks can turn your tests into a house of cards, giving you false confidence and creating hidden technical debt that slows teams down. In complex workflows — like payments or authentication — mocks fail to capture the true behavior of interconnected services.