Events / Callbacks

Do you think it would be possible to expose an event emitter on the engine which fires events when jobs are completed/failed?

I'd like to be able to do things in my application in response to jobs completing without having to poll for changes.

If such a system were implemented, then an additional Job convenience method of "event" would also be helpful for allowing me to emit an event manually.

The immediate and most obvious downfall of a system like this would be whom receives the event, in a distributed system you may pick up an job that was enqueued on a different node. Would you expect the enqueuing node to receive the event, or the node running the job?

For my use case it's absolutely fine that that stays a problem for the user in user land, and that the node that processes the job receives the event.

Are there any glaring issues which make this non-viable?

Start by tracing the engine's job completion and failure handling, then review the Job API described in the issue. Determine how an event emitter and a manual Job event would fit, including which node receives events in distributed execution. Done requires a documented event contract and a settled delivery model.