Matthew Smit worked on the facebook/buck2-prelude repository, focusing on improving Windows compatibility in build systems. He addressed a critical bug in the protobuf generation process, where incorrect path separators in copy commands caused the gRPC plugin to become unreadable and blocked Windows builds. Using his expertise in Bzl and build system internals, Matthew implemented a fix that aligned Windows genrules with Linux and macOS behavior, restoring readable plugin output and resolving cross-platform build errors. This targeted engineering effort enhanced build reliability and streamlined developer onboarding for Windows users, demonstrating a deep understanding of platform-specific challenges in large-scale build environments.