I completely agree with you regarding debugging. Especially with Lambda. But App Engine allows you to connect a python REPL directly to your app in the cloud. It doesn't get any better than that. And I've noticed that because mobile developers don't get to pick much to develop to (the device maker dictates) they seem to move much faster than your typical server-side developer who bit twiddles VMs, Dockerfiles and distributed services much more than they admit with the time left to write actual functionality much lower. Too much choice is also a prison.