This is over a decade old, but the general idea here is to do what you can to simulate overloaded database so that the Rust and NodeJS code is tested to gracefully report to the end-user (and log to server operators) that the database backend is failing.

https://www.endpointdev.com/blog/2012/11/how-to-make-postgresql-query-slow/

Lemmy has been falling over to nginx 50x errors under overloads, denial of service situations. Try to exercise the error behavior and harden the Rust and NodeJS code.