If you develop an app long enough, you’ll probably end up with a number of env vars. You probably have some variation of DATABASE_URL, CACHE_URL, DEFAULT_STMT_TIMEOUT, etc.

This is fine when you only have a few env vars, but at some point it breaks down and becomes hard to figure out what each env var does / comes from.

This is why I think it’s wise to prefix env vars. This serves a couple purposes, you can more easily grep for env vars, and it helps separate app env vars from env vars that exist on the host.

As they say:

Namespaces are one honking great idea – let’s do more of those!
– The Zen of Python