Consider moving to BullMQ

[dwene]

Bull has been moved to maintenance mode (https://github.com/OptimalBits/bull#-news-and-updates), and the bull team has completely rewritten Bull as BullMQ in typescript (https://docs.bullmq.io/).

They fixed a lot of issues in Bull (stalled jobs, concurrency), which I think would really help the event-bus service thrive and not get blocked by long running jobs.

[olivermrbl]

Thank you for reporting this one @dwene. We will definitely investigate a migration to BullMQ, and move on it in the near future :)