Having to manage callback control flow by hand. There's a lot of research surrounding CPS-transformed code (look at Orbit (http://people.csail.mit.edu/riastrad

Having to manage callback control flow by hand. There's a lot of research surrounding CPS-transformed code (look at Orbit (http://people.csail.mit.edu/riastradh/t/adams86orbit.pdf http://people.csail.mit.edu/riastradh/t/adams86orbit.pdf), for example), but nobody ever needed to manage it by hand. For a more meaningful comparison between Node and Erlang, look at how they handle errors.