The reason that I used redis here is because I wanted it to work even if you scheduled the thing in cron, or have it work when you restarted the process and not give any false messages. Also, putting things in redis makes it easier to integrate it with something else, e.g. a UI, without really having to tool anything.

But yes, at this point it doesn't really need to use redis and if you don't already have a redis-server running it's a bit of unnecessary work to get the proof of concept working.