Rails

A deadlock Postgres can't see

A Rails migration waited forever on a lock held by its own transaction, through a second connection pool. Why Postgres' deadlock detector can't catch that, how to spot it in pg_stat_activity, and why the logs were empty.

Why parallel deploys waited on each other

Several Railyard deploys at once queued behind each other and froze the dashboard. The shared resources one kind of work could fill, how I split them, and the two bugs the fixes created.

One door for every deploy

Railyard had nineteen places that could start a deploy, each with its own copy of the rules. How I moved every one of them behind a single model method, and the table-driven test that keeps them there.

Why my Rails dashboard took two seconds to load

A performance postmortem on Railyard's Rails and Hotwire control plane: an image build on the live box, a hidden tab that streamed logs into Solid Cable, and a page that rendered fourteen hidden tabs to show one.

Moving Railyard's control plane from Fly.io to one EC2 box

Why the Railyard control plane needed four Fly machines and a dedicated IPv4, how it runs now on one Graviton EC2 instance with RDS and Caddy, and the cache-table bug that returned 500 on every request after the cutover.

Hardening a deploy platform against apps I didn't write

How I harden Railyard against open-source Rails apps: deploy each one unmodified, group the failures into classes, fix the class on its second occurrence, and only call something fixed when a fresh build reproduces it.

Why Railyard is a Rails app and a Go agent joined by one proto file

Railyard splits into a Rails control plane that decides and a Go agent that does the work on each server, joined by a gRPC contract. How the contract is laid out, how build logs stream, and what the split costs.