One of the components of my OpenTelemetry demo is a Rust application built with the Axum web framework. In its description, axum mentions: axum doesn’t have its own middleware system but instead uses tower::Service. This means axum gets timeouts, tracing, compression, authorization, and more, for free. It also enables you to share middleware with applications written using hyper or tonic. — axum README So far, I was happy to let this cryptic explanation lurk in the corner of