It’s great on esp32 with MicroPython. Even has support for server sent events (SSE). Paired with htmx, SSE gives some fun intetactive web experience for iot devices - instant GPIO status indicators etc. Loved tinkering with it. The source code is very readable too.
It is a single 765-line file with routing, JSON handling, cookies, streaming, and TLS. Created to provide a web server for IoT devices.