The fewer moving parts bit is key. It was a government project, written by one team (us) to be maintained by another. The data that needed to be expunged was

The fewer moving parts bit is key. It was a government project, written by one team (us) to be maintained by another. The data that needed to be expunged was user signup data, upon completion the record was sent to a CRM and the Redis record destroyed. If the signup wasn't finished it's automatically removed after 12 hours. Referential integrity wasn't really a problem, emails are unique and if we clash the two records are auto-merged by the CRM. Setting up scheduled tasks, triggers, partitioning, cron, etc, is just more things that can go wrong. If they go wrong _and_ go unnoticed we end up with piles of data we shouldn't have. That would be many different kinds of bad. Doing `redis.set(k, v, ex: 12.hours)` or whatever is just easier.