Top IT Service Providers 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.