[st0p]

Why not use Varnish? POST messages of 500 bytes could easily be rewritten / proxy'd to GET requests. That might not be 100% restfull but seems like a lot less work. On our production environment Varnish always responds in less then 2 ms. Even on my development VM I never see response times > 5 ms. It has all the other requirements they state.

Perhaps I'm prejudiced because Varnish has proven to be such an awesome caching mechanism (we still use Redis as a key/value store), but this seems like NIH.

[leetrout]

Varnish is actually difficult to use for POST requests unless you know C and can tweak the existing vmods. I just came off the same basic requirements and ended up going with Nginx (OpenResty) with Lua & Redis.