Echo JS 0.11.0

There is Promise.all though  ¯\_(ツ)_/¯

The bigger issue is that if you have more than around 6 connections to a single resource they will be delayed.  It's not so mucha matter of grouping the requests to deliver at the same time as it is about limiting server requests and resource contention.

Websockets would be another solution.

Thats exactly what graphql solves

graphql isn't free though... there is a *LOT* of boilerplate depending on your object graph structure and actual data source implementations.  It doesn't always make sense to jump through those hoops... then again, it doesn't always make sense to go through extra abstractions to group your AJAX requests either.