Testing Your Own Code Questions

Ability to validate and reason about their own implementation before and after committing code. Candidates should demonstrate how they identify edge cases and invalid inputs, mentally run through test cases, write small unit tests, use assertions and invariants, reason about concurrency and error handling, use debuggers and static analysis tools, and refactor code to improve testability. Include practices such as quick local smoke tests, simple regression checks, and using code review feedback to uncover missed scenarios.