Engineering at Meta(@Meta_Engineers):🧠 Most AI bug-catching tools review your code the way a human reviewer would, only faster. What if the AI wrote a test that proved the bug instead? That’s Catching Just-in-Time Tests (JiTTests) — a novel approach where LLMs generate executable tests designed to fail, surfacing behavioral changes in a code change before it lands. After a year of research, it’s now part of Meta’s infrastructure. ✅ 589 engineers have engaged with it, reporting a 60% true-positive rate 📈 In the first half of 2026, it helped catch 74 privacy SEVs at the diff stage, lowering overall privacy SEV occurrence by 20% 🔗 Read how it works: https://t.co/dxVljpTmyB 📄 Read our FSE 2026 paper, “Just-in-Time Catching Test Generation at Meta”: https://t.co/YKnj30xOn6 #AI #SoftwareEngineering #SoftwareTesting #DeveloperTools #Engineering

2026.11.09 16:30

🧠 Most AI bug-catching tools review your code the way a human reviewer would, only faster. What if the AI wrote a test that proved the bug instead? That’s Catching Just-in-Time Tests (JiTTests) — a novel approach where LLMs generate executable tests designed to fail, surfacing behavioral changes in a code change before it lands. After a year of research, it’s now part of Meta’s infrastructure. ✅ 589 engineers have engaged with it, reporting a 60% true-positive rate 📈 In the first half of 2026, it helped catch 74 privacy SEVs at the diff stage, lowering overall privacy SEV occurrence by 20% 🔗 Read how it works: 📄 Read our FSE 2026 paper, “Just-in-Time Catching Test Generation at Meta”: #AI# #SoftwareEngineering# #SoftwareTesting# #DeveloperTools# #Engineering#