[dmix]

> Nowadays the language (when it is as slow as Ruby) is most likely to be the problem.

These days the main issue why web apps are slow or fragile is because they are huge React apps that do way too much in the browser than they need too. The response time from the server is rarely the issue unless you're doing heavy analytics. High end React shops do some crazy optimization to try to compensate for this fact. Linear is the only one I've seen do it well with JS.