Part 8
2 chapters
Performance & transport
Reason about back-end I/O concurrency and HTTP/2-3 behavior behind the API.
Chapter 18
Back-end I/O concurrency
Serve many concurrent requests that each wait on I/O without exhausting threads: Quarkus blocking worker pools versus reactive and virtual threads, and Python's async event loop versus a thread pool under the GIL.
Chapter 19
REST over HTTP/2 & HTTP/3
What changes for a REST API under the hood across HTTP versions: HTTP/2 multiplexing and HPACK, TCP head-of-line blocking, and HTTP/3 over QUIC with stream isolation, connection migration, and 0-RTT.