DejaBug

DejaBug: your team's past bugs, replayed as training cases. THE PROBLEM A new developer's hardest job is debugging code they did not write, and the first real practice often happens in production, under pressure. AI assistants add a new risk: when the AI writes the fix, the new hire skips the practice that builds the skill. Yet every repository already holds the missing course: hundreds of real bugs, each with a fix and a test that proves it, unused because turning one into an exercise by hand takes hours. In Cortex's 2024 survey, 72% of engineering leaders said new hires need over a month for their first 3 meaningful pull requests. OUR SOLUTION DejaBug turns a repository's bug-fix history into proven cases in a detective game. 1. Mine: find commits that fixed a bug and came with a test. 2. Prove: in parallel git worktrees, restore the code just before the fix and run the fix's own test. It must fail 3 out of 3 times, then pass on the real fix. Anything else is rejected with a reason. 3. Brief: IBM Granite on watsonx.ai, or IBM Bob Shell with our Deja Forger mode, writes a spoiler-free case file: symptoms, evidence, three hints, the lesson. 4. Play: the player debugs in IBM Bob with Deja Mentor, a read-only Bob mode that coaches with questions but cannot write the fix. 5. Debrief: XP, ranks, badges, and your time and diff next to the original team's. TARGET USERS Players are new hires and junior developers. Buyers are engineering managers at companies with 50 to 5,000 engineers. Open-source maintainers can publish free case libraries. HOW THEY USE IT Install DejaBug and paste any GitHub repository (Go or Python, with tests) into Settings. The Forge shows the proof live: red lights for failing runs, green for the pass. On the Case Board the player takes a case and gets a clean copy of the code with no later history. They fix it in IBM Bob with Deja Mentor and press Run the tests: the engine runs the certified test on their real files. Green means CASE CLOSED. WHAT MAKES IT UNIQUE Replaying real fixes is how AI models are benchmarked; DejaBug uses it to train people. Every case is proven by the project's own tests, and the mentor cannot write code, so the learning stays with the developer. RESULTS IBM/sarama: 2,889 commits scanned, 703 fixes found, 27 proven cases. IBM/python-sdk-core: 31 proven. google/uuid, never seen before, went from a pasted link to a proven case in about 90 seconds. 56 cases, none written by hand. BUSINESS VALUE The US expects about 106,100 developer and tester openings a year (BLS). DejaBug is free and open source; teams would pay for a shared case library, leaderboards and a manager's view. If it cuts ramp-up by two weeks (our assumption), a company hiring 20 engineers saves about $103K a year. Try it: https://ahammadshawki8.github.io/DejaBug/ Code: https://github.com/ahammadshawki8/DejaBug Video: https://youtu.be/AQhqBSi0cAY Pitch Deck: https://github.com/ahammadshawki8/DejaBug/blob/main/docs/submission/DejaBug%20Pitch%20Deck.pdf