Developed a performance-focused update for the bitcoin/bitcoin repository, introducing a Block Tree Ancestor Retrieval Optimization that enables efficient ancestor queries within the block tree structure. Leveraging C++ and advanced data structures, the solution implemented a skiplist-backed GetAncestor function, reducing traversal complexity to O(log N) and improving both speed and usability for chain analysis tasks. The work included publishing a C++ convenience wrapper and comprehensive tests to ensure correctness and maintainability. By exposing the new API surface, the update reduced CPU usage during ancestry queries and enhanced developer ergonomics, supporting easier integration and long-term maintenance within the codebase.