Igor worked on stabilizing the build system for the elixir-lang/expert repository, focusing on ensuring compatibility with the latest nixpkgs. He updated the build process using Nix, emphasizing careful dependency management and build system configuration to minimize risk. By maintaining the existing flake.lock, Igor achieved build compatibility without introducing unnecessary changes, aligning his updates with ongoing NixOS/nixpkgs developments. His work addressed the challenge of keeping the Expert application’s build reliable amid upstream changes, demonstrating a methodical approach to system stability. Over the month, Igor contributed one feature, reflecting a focused and technically sound effort in build system engineering.