Claude builds a SQLite parse_number() extension in C and Rust
The counter-intuitive result is that hand-optimised C can beat Rust on speed while staying 20x smaller, and that a single conversational prompt was enough to get Claude to close a 3.5x performance gap. Developers weighing C versus Rust for SQLite extensions get concrete binary sizes and nanosecond benchmarks to compare. The workflow itself — prompting, benchmarking, then asking the model to formalise findings into a repo — is a reusable pattern for agent-assisted engineering.