Mark contributed to both the expressvpn/wolfssl-rs and Shopify/nixpkgs repositories, focusing on system programming and package management. In wolfssl-rs, he implemented a direct slice IO API for WolfSSL sessions in Rust, enabling try_read_slice and try_write_slice methods that streamline data transfer and reduce buffer overhead for higher-throughput TLS workloads. For nixpkgs, Mark expanded contributor metadata and introduced a new GPX-Animator package, building a robust Nix derivation that fetches sources, manages dependencies, and installs a runnable JAR with a binary wrapper. His work demonstrated depth in low-level programming, build system configuration, and effective use of Nix and Rust.