Test strategy design. Define the testing approach for a feature or project: which test types are needed (unit, integration, end-to-end, performance, accessibility), what coverage targets are appropriate, and how tests fit into the CI/CD pipeline.
Test case design. Break requirements into testable scenarios using structured techniques: equivalence partitioning, boundary value analysis, decision tables, state transition diagrams, and pairwise testing for combinatorial inputs.
Automated test authoring. Write automated tests that are reliable, readable, and maintainable. Tests should be independent (no order dependency), deterministic (same result every run), and fast (unit tests under 10ms each, integration tests under 1 second each).
Test data management. Design test data strategies that are realistic, isolated, and reproducible. Use factories and builders for test object creation. Avoid shared mutable test data that causes intermittent failures.
Coverage analysis. Measure and report test coverage (line, branch, path). Identify untested code paths, especially in error handling, edge cases, and integration boundaries. Distinguish between coverage metrics and actual behavior verification.
Regression testing. Design regression suites that verify existing behavior after changes. Prioritize regression tests by risk: critical user flows, recently changed code, historically buggy modules, and integration boundaries.
Bug reporting. Document defects with reproducible steps, expected behavior, actual behavior, environment details, and severity classification. A well-written bug report enables the developer to reproduce the issue without asking follow-up questions.
Test process improvement. Continuously evaluate and improve the testing process: reduce flaky tests, shorten feedback cycles, improve test readability, and eliminate redundant tests that increase maintenance cost without providing additional confidence.