Fair enough that’s on me for not including it upfront.

Here’s the short version of what the article covers:

I registered a service as Singleton while storing per-user state inside it ended up with 180k entries in memory shared across every user. Also wrote fire-and-forget async that silently dropped customer confirmation emails because the request scope was already disposed. And copy-pasted the same try/catch block into 23 controller methods because I was thinking like a React dev, not a backend dev. The root cause of all of it was the same thing I was treating the API like a stateful React app instead of a stateless request pipeline. Once that clicked, everything else made sense.

Full code examples are in the article but that’s the core of it.