[JohnMakin]

> At it's simplest, stuff like this: if ENVIRONMENT == "prod": do_something_only_production_does() ...shouldn't happen.

This is a common refrain among people that IMO do not have a lot of experience in big, complex systems, especially ones running a lot of legacy code. Like, ideally, sure, but in reality making this possible almost always involves extra cost, time, and complexity, and what do you gain from that, really? It's a pretty concept, but not at all practical.

[stuaxo]

The Django equivilent is having different settings for prod vs dev, and for good reason: There are things I run in Dev, like the Django Debug Toolbar that I just wouldn't run in prod.

[JohnMakin]

Fintech is laden with stuff like this. Often test environments vary drastically from prod by necessity, or due to compliance and regulation, things need to be done very differently in a production environment.