Testing

At Level 1, you're beginning to learn that testing is a key part of building reliable software. You may not write tests yet, or you rely heavily on others to tell you what kind of test is needed. Your primary focus is still on getting the feature or fix to work, but you're starting to understand the role of tests in making sure it stays working. This level is about awareness and exposure—seeing how and where testing fits into the workflow.

At Level 2, you write basic tests without being asked. You understand that testing isn't separate from your work—it's part of how your work gets done. You begin to think about what could break and how to prove it won't. You may still need help choosing the right type of test or understanding edge cases, but you now include tests as part of most changes.

At Level 3, testing is a core part of how you design and deliver software. You write tests with intent and clarity, balancing speed, coverage, and maintainability. You consider the risk profile of your code and tailor your tests accordingly. You also help shape the team's overall testing approach. Your tests help others understand the system and prevent regressions.

At Level 4, you scale good testing practices across teams. You proactively identify where testing is failing the organization—whether through gaps, flakiness, confusion, or lack of tooling—and drive change. You shape the culture of testing, not just the coverage. Your impact is felt in how confidently teams ship, how quickly they debug, and how easily new engineers get up to speed.

At Level 5, you influence how an entire engineering organization approaches quality and confidence. You don't just write or guide tests—you shape mindsets, standards, and systems that enable thousands of confident changes per day. You lead cross-functional efforts to balance speed, safety, and simplicity at scale.