Tbh I had no idea this was even a thing until recently. I've been working with Rails for a while now and somehow never came across it. So let me explain it the way I understood it. You know how we normally do associations in Rails, User has many Posts, Post belongs to User. Two different models, two different tables. Simple. But what if a model needs to reference itself? Like same table, same mode
Most cloud sustainability tools are built for sustainability officers. They pull three-month-old billing data, run it through a proprietary model, and produce a PDF that engineers never see. By the time you know your us-east-1 cluster emits twice as much as us-west-2 would have, it's been running for a quarter. The architecture is locked in. The carbon is already burnt. The only moment you can act
Let me rewind to a Tuesday afternoon I’d rather forget. We had a Rails monolith that had grown fat and happy over five years. The dashboard—a beautiful, chart-filled monster—was running a 12-second query every time the CEO clicked “refresh.” Twelve seconds of GROUP BY, COUNT(DISTINCT), and LEFT JOIN hell across a million-row events table. The CEO didn’t yell. He just stared at the spinning cursor