[aclave1]

I am in no way affiliated with this project, but my assumption is that since this uses workers(separate servers) to process the background jobs - they could be on completely separate machines. If you use redis for job storage, they can all communicate without having to talk back to the master server.

[askmike]

You can also do that with sqlite: have workers query for data and lock records when they are working on it. (people have been implementing job queues in SQL based environments for decades). The point of using sqlite is that it's not something you need to install and manage separately, or something that acts as a broker. (sqlite would be very slow as the workers need to poll for jobs).

[eropple]

Polling is not the worst thing in the world; when using reliable queueing and BRPOPLPUSH TaskBotJS does poll, and Redis handles it okay. SQLite is more just emphatically Not A Good Network Database, and the developers themselves say so.