In November 2024, Sebastian Firsching contributed to FormalBook and comprehensive-rust by delivering features focused on documentation, formal verification, and robust testing. He authored onboarding and contribution guidelines for FormalBook, enhancing community engagement and maintainability. Using Lean and LaTeX, he formalized Van der Waerden’s permanent conjecture, providing precise mathematical declarations and references. For comprehensive-rust, Sebastian expanded arithmetic edge-case test coverage in Rust, addressing scenarios like division by zero and zero operands to reduce risk and ensure correctness. His work demonstrated depth in technical documentation, mathematical proof, and unit testing, emphasizing reliability and clarity without requiring major bug fixes during the period.