@coco thank you very much!
The thing I didn't mentioned in initial post is that performance is used by third party module - box2D. And one can't import there
And with your advice I've end up adding it to to the global scope in my arena.config

While trying to host my server code on Colyseus Arena, I've come up with a problem - I can't use performance.now() because it is undefined. Although it works fine on local server.

For illustration I took a simple server template and put logging of performance.now() in onJoin method

And with a simple client that just joins the room I have a following log

Is there any idea why it could be the case? Is there any workaround?