Matti Jokinen contributed to the riscv/sdtrigpend and pq-code-package/mlkem-c-aarch64 repositories, focusing on cryptography and performance optimization for RISC-V hardware. He clarified security documentation by refining explanations of instruction timing risks in scalar cryptography, improving technical writing for developer guidance. In pq-code-package/mlkem-c-aarch64, he implemented RISC-V Vector Extension support and direct cycle counting via PMU access, expanding benchmarking capabilities across 32-bit and 64-bit RISC-V platforms. His work involved C, assembly, and Makefile integration, demonstrating depth in low-level programming and embedded systems. These contributions enhanced both the clarity of security documentation and the performance measurement infrastructure.