Build faster with Buck2: Our open source build system

This post introduces Buck2, Meta's new open-source, large-scale build system written in Rust. It details the architectural changes from Buck1, including the separation of core and language-specific rules, a single incremental dependency graph, and integration with remote execution and virtual file systems. It highlights performance improvements, with builds completing twice as fast as Buck1, and discusses the user and rule author perspectives, including new features like dynamic output for OCaml dependencies and transitive sets for C++ link dependencies.