I’ve been using it since it was in beta. Simple, clear, fast.
The company I’m working for now keeps trying to add more and more functionality using Redis, that doesn’t belong in Redis, and then complains about Redis scaling issues.
Sure, there's persistence but it always seemed like an afterthought. It's also unavailable in most hosted Redis services or very expensive when it's available.
There's also HA and clustering, which makes data loss less likely but that might not be good enough.
For the people wondering who would ever use Redis this way, check out Sidekiq! https://sidekiq.org/ "Ephemeral" jobs can be a big trade-off that many Rails teams aren't really aware of until it's too late. Reading the Sidekiq docs doesn't mention this, last time I checked, so I can't really blame people when they go for the "standard"/"best" job system and they are surprised when it gets super expensive to host it.