An obsessive focus on performance. In the above benchmarks, uv is 8-10x faster than pip and pip-tools without caching, and 80-115x faster when running with a warm cache (e.g., recreating a virtual environment or updating a dependency). uv uses a global module cache to avoid re-downloading and re-building dependencies, and leverages Copy-on-Write and hardlinks on supported filesystems to minimize disk space usage.