So, I’m wondering if there is a way to say “run this job anytime you can after a specific time”.

It works exactly as you described. Enqueue_in/at puts the job in a ZSET with scheduled time as the score. When the current time is > the scheduled time, exq will push the job to the end of the queue. The exact time of execution depends on how many jobs are pending in the queue.

That’s a difficult question, I also don’t generally use Exq, I just have one project I maintain that uses it. From what I can tell in the config the concurrency is set to 3 and then job queues each have their own concurrent values set (max is 3).

Concurrency is handled per queue, the global config is just a fallback value to be used if you don’t specify per queue concurrency.

So I’m not sure if we’d be handling 3 jobs at once or 11 (sum of all concurrencies per queue)

it would be the later