Colm Donelan focused on improving build stability for the google/XNNPACK repository by addressing a critical SME2 compatibility issue in September 2025. He resolved a blocking build failure in the GEMMBenchmark component by updating the constructor signature from size_t to ConstantOrFunction in both C++ source and header files. This change preserved API compatibility, ensuring that SME2-enabled builds remained stable without requiring modifications from downstream consumers. Colm’s work demonstrated a strong command of C++ and build systems, with careful attention to type safety and release risk mitigation. The fix reinforced ARM SME2 configuration reliability and maintained accessible performance paths for users.