Top Big Data & BI Companies for JavaScript

JavaScript spans more ground than any other language on this list. It runs in every browser, on servers through Node, and inside mobile and desktop applications, so a firm listing it may be doing front-end interface work, back-end services, or both.

The useful clarification is which part of the stack, and with what. Front-end work is dominated by a handful of frameworks and the choice affects hiring for years afterwards. Back-end JavaScript competes with other server languages and is chosen for good reasons and bad ones. Ask why they would pick it for your project specifically — a clear answer indicates a team choosing tools, and a vague one indicates a team using whatever they already know.