[di4na]

For #3 in general the advice is a NIF or a Port to an engine (polar is a good example) or to use Luerl

For #2 i know nothing about this kind of stuff

For #1 it depends a lot. Something like Oban can be enough, or Ulf Wiger's Job or Broadway. These tends to be more ad hoc and extracted to independent services. It depends a lot of what kind of constraints you have for these workflows. There are lot of options but they are all more specific to use case and constraints than these broad projects that try to do it all.