How do you think, is it a good idea to write own web-server for a high-loaded project with built-in native code comparing to nginx + C++ module? Probably, productivity gains will be negligible?
And what about the safety of this approach (С++ module for nginx) compare to usage of interpreted programming languages?
Don't do it.
Your time will be better spent investigating how you can improve the caching of your resources. Investigate HTTP's Cache-Control, conditional GET, Transfer-Encoding (ie gzip) & Range headers (in that order).
If you use ORM investigate wether you can enable persistence caching to eliminate network hops to your DB.
Also, investigate the use of a CDN and caching reverse proxy such as Varnish.