In this talk we’ll discuss antlir2, Meta’s solution to building container and bare metal operating system images. We’ll talk about how we have built performant, hermetic and deterministic image building infrastructure on top of buck2 (Meta’s new open source build system) and how we enable users to compose their own multi-language projects with full operating systems, write tests and deploy their images. Along the way, we’ll also cover how antlir2 wrangles dnf and other upstream tooling to behave more predictably for better, more reliable images.