Hey everyone, let's say you're programming an app that takes user inputs and does an action after X seconds, but this needs to be rather precise (0.1s if possible or 1s max)

Assuming we have 100 000 users, and each user can have at most one task queued and those tasks can be cancelled / overwritten

I don't think spawning a thread for each user's task is great, it's faulty to machine reboot etc, so how would you do it ?