django-redis

django-redis is the cache backend most Django apps reach for when the built-in one isn't enough. Django ships with caching, but it's basic. This swaps in Redis, the fast in-memory data store, as your cache and session store, with all the knobs production actually needs. BSD licensed, maintained under the Jazzband collective, free.

What you get over rolling your own: native Redis URL connection strings, pluggable serializers, compression in half a dozen formats, primary and secondary replication, Sentinel support, distributed locks, and bulk operations by pattern. These are the things you don't realize you need until traffic shows up and the default cache falls over. It's a library, so running it is a pip install and some settings, but it assumes you already have a Redis server to point at.

Shipping a Django app of any real size? This is close to a default choice, not a decision you'll agonize over. Solo projects can lean on the simpler built-in cache until they outgrow it. Teams running anything in production will want what this gives them. Free at every size, nothing to buy.

The catch isn't django-redis, it's Redis itself. You still have to run, secure, and scale a Redis instance, and the recent licensing drama around Redis the product is worth knowing about even though this client doesn't change it. The library is the easy part.