Yes, Go has higher development efficiency than Rust, especially for new comers. For a storage engine, the most important thing is stable. We focus on write right and stable codes. Rust's compiler is quite strict. Which is good for write right codes. We have many good programmers who is very good at writing Rust. So we do not suffer from the low development efficiency. About the libraries, we could get most of we need. But some were missing when we begin to develop TiKV (GRPC/HTTP2 for example). But thanks to Rust Team/Community, they give us great supports. GRPC for Rust is available now. We also contribute back to the community. We develop prometheus client for Rust. The Rust community is active and helpful. So we do not worry about the lack of libraries.