It indeed makes sense to look at on OS. You might want to start with a simple one, like FreeRTOS - which is more or less just a task scheduler at core. I would

It indeed makes sense to look at on OS. You might want to start with a simple one, like FreeRTOS - which is more or less just a task scheduler at core. I would recommend not to start with coroutines in the beginning if your main focus is scheduling. In the end coroutines and async/await is about building a userspace scheduler on top of a scheduler that already exists in the OS, so you just get twice the amount of logic. However the schedulers used in userspace are often a lot more trivial than the OS ones, since they don't support preemption or priorities. Erlang might be the exception and an interesting thing to look into.