Do custom events run in parallel or sequential?

Sorry, I know this has been covered but I’ve seen conflicting information so asking again.

If I have a workflow that has step 1 do x, step 2 trigger custom event, step 3 do z, will my workflow pause at step 2 until the custom event is done running to completion before moving to step 3?

Yes. The step 3 will run only after the custom event finishes.

Custom events themselves are clientside actions and will definitely run in sequence. You can run them in parallel too if you need them too. All you need to do is use “Schedule a custom event” and set them to run at the same time.

There will be a very minor lag (microseconds).