Hey Product Hunt! I built SDET Code because there was nowhere for QA Engineers to practice the skill that actually matters in their job: writing tests that find real bugs. Every coding platform out there is built for software engineers writing algorithms. But QA engineers don't reverse linked lists -- they read code, reason about edge cases, and write test suites that expose hidden defects. Those are completely different skills. How it works: Each challenge presents Python code with intentionally seeded bugs (mutants). You write pytest tests to catch them. Your score is the percentage of mutants your tests kill -- your Kill Ratio. What makes it different: - Mutation testing as the core mechanic -- the gold standard for measuring test quality, turned into a learning tool. - Runs entirely in your browser via Pyodide (WebAssembly Python). No setup required. - AI coaching with GPT-5.4 Deep Reasoning for strategy analysis and GPT-5-nano for quick interactive hints -- both tuned for test engineering. - Career rank progression: Rookie to Master Auditor, based on actual skill measurement. 339 challenges. 6 real-world domains. Free to start. I'd love your feedback. What kinds of bugs do you find hardest to catch? That determines what we build next. Try it at https://sdetcode.com

SDET Code

Write tests. Find bugs. Level up your QA career.

Write tests. Find bugs. Level up your QA career.