Expecting that any key in redis will be there next time you read it is a ticking timebomb. Redis is not a database. It's a cache.

Unless you're using AOF mode with fsync always, you can lose writes. If you're doing that, you should be using a real database instead.

The first line of redis.io:

> The open source, in-memory data store

I don't mean to knock redis. I love redis. I implore you to benchmark Redis in FSYNC_ALWAYS vs Postgres. I encourage you to benchmark it as well with FSYNC_EVERYSEC and understand the tradeoffs that makes - Postgres is still very competitive with EVERYSEC in most workloads, and with a lot less tradeoffs in data reliability.

Yeah, in-memory. That should tell you it's not a persistent data store.