War Story: Debugging a Ktor 2.2 Coroutine Leak in Kotlin 2.0 Microservices

At 3:17 AM on a Tuesday in Q3 2024, our production Kotlin 2.0 microservice fleet hit a 92% memory utilization threshold across 140 nodes, traced to a silent coroutine leak in Ktor 2.2’s request pipeline that had been bleeding 12MB of heap per second for 72 hours. We lost $14k in SLO credits before we found the root cause. 📡 Hacker News Top Stories Right Now A Couple Million Lines of Haskell: Production Engineering at Mercury (78 points) Clandestine network smuggling Starlink tech into Iran to b