June 2025 monthly summary focusing on key accomplishments for foxglove/mcap. Key features delivered include MCAP Rust writer configurable compression settings and multithreaded compression defaults, enabling users to tune compression level and threading for performance and resource usage. Release readiness was achieved via a version bump to 0.19.0 in Cargo.toml as part of the release process, supporting downstream packaging and compatibility. No major bugs fixed this month; the focus was on feature delivery, performance improvements, and release hygiene. Technologies demonstrated include Rust, MCAP writer internals, zstd and lz4 compression, multithreading, and Cargo-based versioning. Business value: improved write throughput, configurability, and stability for MCAP users and downstream tooling.