Elixir 1.19 brings enhanced type checking, broader type inference, and faster compilation

Elixir 1.19 brings improved type inference and stricter type checking to anonymous functions and protocols in the language’s type system. These changes offer developers stronger safety guarantees and better tooling when writing and maintaining code.

Alongside these type system enhancements, the new release focuses heavily on compilation speed for large codebases. The Elixir compiler now integrates two optimizations that can reduce build times by up to four times. Another notable change is the shift to lazy module loading, which relieves the code server bottleneck during compilation. This allows for more parallelization, resulting in reports of more than two times faster build speeds on sizable projects.

Building on these performance improvements, Elixir 1.19 introduces an environment variable, MIX_OS_DEPS_COMPILE_PARTITION_COUNT. This new option lets mix deps.compile run dependency compilation tasks in parallel, accelerating builds in projects with many dependencies. Furthermore, Elixir now officially supports Erlang/OTP 28.1 and later, keeping the ecosystem in line with recent Erlang releases. The release also marks Elixir’s first following OpenChain compliance, reflecting software supply chain best practices. Additional updates include improved option parsing, increased ExUnit debuggability, better test performance, and several other refinements.