Programming languages endorsed for server-side use at Meta

What this post added

This post details Meta's internal guidance on supported server-side programming languages, with Rust being the latest addition. It explains the criteria for a 'supported' language, the rationale behind language decisions (performance, security, operational risk, expertise, developer experience), and the specific recommendations for Hack, C++, Rust, and Python based on use cases (business logic, performance-sensitive back-ends, CLI tools, data science, ML, and Instagram). It also mentions other supported languages like Java, Erlang, Haskell, and Go for specific use cases.