DHH's agent-written Campfire rewrites show unread code leaves key trade-offs to a coin flip

Piotr Sarnacki found the agent-built Rust and Elixir versions made different unprompted calls on backwards compatibility, Redis, and blocking database work, and the Rust one delivered about 1% of notifications under heavy load because of a 256-slot broadcast channel. Rerunning at a constant 100 POSTs/s, he argues dropping lagging clients beats Elixir's unbounded mailboxes, which reached 1.8GB and event delays near 180s.