Unbounded Concurrency is a Foot Gun

Bluesky went down for half its users for about 8 hours on Monday. Jim Calabro wrote up an excellent post-mortem that is worth reading in full, but the root cause is something I keep seeing across languages and runtimes, and it&#x27;s worth talking about on its own. One endpoint in their data plane, GetPostRecord , fanned out concurrent work based on the size of the incoming request. Every other…