My favorite ORM is TypeORM. A client insisted we use that, mostly because they were already using it.

Somehow, a few left joins led to ridiculous (talking tens of gigabytes of ram when the whole database itself was at most a hundred megabytes) memory leaks, blowing up the instances.

Turns out, it is a known issue [0], and you’re better off joining by hand.

I won’t complain though. I got a nice blog post out of it.

Now, this wont’ be specific to ORMs, and any dependency could blow up your service by leaking all over the place. But so far it’s been the only one to do this to me.

[0]: https://github.com/typeorm/typeorm/issues/4499#issuecomment-...