We use Node.js with Express and some pretty simple but very effective middleware we wrote to make API development a little more robust, like automatic metrics c

We use Node.js with Express and some pretty simple but very effective middleware we wrote to make API development a little more robust, like automatic metrics collection, logging, proper error handling etc. I have 0 Ruby experience so I can't comment as to how it would compare. I would say neither Go or Node would be a bad choice, each having their tradeoffs. Node honestly is very performant overall given the time in which it takes a developer to code, test and deploy (tradeoffs). Also IMO Node has a little more available in terms of examples and people that have already hit the issues ahead of you. So if time to completion is important, it might be faster for that purpose alone. Then if you find a hot path, work to optimize it etc. For what it is worth too, I hear people complain about Node occasionally and it is usually when they are trying to do longer running tasks, like huge sorts etc. Node is not a good candidate for work that blocks the event loop for long periods, there are better tools for that as you probably already know. The other complaints I hear/see often are when people choose the wrong 3rd party plugins to base their systems on. npm makes it easy to install almost any module, and sometimes that low barrier makes for easy but less than stellar choices; its like anything research the module first and try real scenarios as a POC before committing. Also there are other frameworks other than Express for Node, for example you can check out HAPI which some people have switched to for RESTful API work.