Elixir 1.20 adds type inference, boosts compilation speed, and debuts new compiler options

Elixir 1.20 introduces a notable step forward for this programming language with the integration of type inference and gradual type checking. This system requires no type annotations, enabling Elixir to automatically detect dead code and verified bugs that would fail at runtime, while maintaining a low false positive rate. Developers benefit from improved code reliability without any additional workload.

Following this major change, the updated type system is built around the dynamic() type, marking a departure from approaches found in other gradually typed languages. By relying on this dynamic() foundation, Elixir manages to introduce these checks with minimal disruption to existing development practices.

In addition to language-level updates, Elixir 1.20 delivers faster compilation times, especially for applications running on multicore machines. Synthetic benchmarks now place Elixir’s build tool as the fastest among BEAM languages.

Complementing these improvements, the release adds a new compiler option, :module_definition. This option allows module execution to be toggled between :compiled and :interpreted, potentially offering further performance gains for large projects. It does not alter the resulting .beam files on disk but changes how code inside defmodule blocks is executed during builds.