For context, Eitaro Fukamachi has been working on a whole bunch of things relating to the low-level parts of Common Lisp web development: A fast HTTP parser, a fast URI parser[0], a libuv-based web server[1] (That outperforms Node!), and he's also written Clack[2], which is Common Lisp's Rack/WSGI.
[0]: https://github.com/fukamachi/quri
[1]: https://github.com/fukamachi/woo
[2]: https://github.com/fukamachi/clack