- pola-rs/polars: https://github.com/pola-rs/polars/pull/26823 - ~2.68x median speedup of primitive-to-boolean casting credited to Claude Opus 4.6
- pydantic/monty: https://github.com/pydantic/monty/pull/643 - ~53x speedup (488ms down to 9.2ms) of bytes substring search generated with Claude Code
- numpy/numpy: https://github.com/numpy/numpy/pull/31573 - ~21x speedup of Python datetime → datetime64 conversion, with Claude Code used for profiling and implementing the performance improvements
- apache/datafusion: https://github.com/apache/datafusion/pull/21182 - up to 49x speedup of LIMIT queries by eliminating unnecessary sorts and pushing limits into file scans, generated with Claude Code
- apache/datafusion: https://github.com/apache/datafusion/pull/21651 - ~4.39x speedup of ClickBench Q6 by resolving MIN/MAX directly from Parquet metadata instead of scanning columns, generated with Claude Code
- pola-rs/polars: https://github.com/pola-rs/polars/pull/27958 - ~3.2x speedup of Int8 Series sum, developed with assistance from Claude Fable and Claude Opus 4.8
- numpy/numpy: https://github.com/numpy/numpy/pull/31274 - up to ~1.44x speedup of common small NumPy reductions, with the fast path written by Claude Code and manually refined