> There are a lot of python distributed systems built around in memory stores, like pycos or dask, or built around existing distributed systems like Akka, Casandra, even Redis.

Cassandra and Redis just mean that you have a database-backed application. How do you schedule Python jobs? Either you build your own scheduler that pulls things out of the database, or you use an existing scheduler. I once worked on a Python system that scheduled tasks using Celery, used Redis for some synchronization flags, and Cassandra for the shared store (also for the main database). Building a custom scheduler for that system would have been a waste of time.