In December 2024, Gabriel Caban focused on enhancing the stability and thread-safety of the mozilla/rhino repository by addressing a deadlock issue in the ThreadSafeSlotMapContainer. He refactored core components such as AccessorSlot, IdScriptableObject, LambdaAccessorSlot, MemberBox, and Slot to improve concurrency handling and property access reliability. Using Java and applying object-oriented programming principles, Gabriel introduced new methods for property descriptor management and slot comparison, ensuring correctness under concurrent conditions. His work reduced the risk of hangs in multi-threaded environments and demonstrated a deep understanding of concurrency and refactoring, resulting in more robust thread-safe object support for Rhino.