Software Engineer (SWE) Skill Level 3. Experience required to support software development and full life cycle testing of mission systems including the design, development, and maintenance of test plans/cases/processes, the creation and maintenance of test environments and automated test capabilities, the performance of Integration & Testing and Acceptance Testing, and the reporting and tracking of problems through their resolution. Knowledge of test automation using Python, performance/load/stress testing, data interface testing, user interface testing, security testing, code coverage tools, and systems integration testing.