Multi Layer Testing Architecture Questions

Designing a comprehensive testing strategy across multiple layers to ensure quality and reliability. Core elements include the testing pyramid and the role of unit tests, component and integration tests, API tests, end to end and system tests, performance and load testing, security and penetration testing, and exploratory testing; test automation and continuous integration and continuous delivery pipelines, test data management and environment provisioning, mocking and contract testing practices, test flakiness mitigation, and how to allocate testing effort to balance speed and risk.