Reasons for node: * Testing/running code that will run on a browser javascript vm outside of the browser * Developer familiarity * Reduced context switching

Reasons for node: * Testing/running code that will run on a browser javascript vm outside of the browser * Developer familiarity * Reduced context switching * Reasonably good asynchronous performance given the above * TypeScript, given the above * Shared backend/frontend code(SSR, etc etc) Interestingly I wouldn't really want to reach for any of your alternatives as a general substitute for NodeJS/TypeScript.. C# or F# perhaps.