I build database-driven web sites. Previously I have used Perl or PHP with MySQL.
Now I am starting a big new project, and I want to do it in the way that will result in the most responsive possible site.
I have seen several pages here where questions about how to optimize PHP are criticized with various versions of "it's not worth going to great lengths to optimize PHP since it's an interpreted language and it won't make that much difference".
I have also heard various discussions (especiallon on the SO podcast) about the benefits of compiled vs. interpreted languages, and it seems as though it would be in my interests to use a compiled language to serve up the site instead of an interpreted language.
Is this even possible in a web context? If so, what would be a reasonable language choice?
In addition to speed one benefit I forsee is the possiblity of finding bugs at compile time instead of having to debug the web site. Is this reasonable to expect?
What you can do is what multiple heavy-traffic websites do (like Facebook or Twitter), aka write your "CPU consuming" algorythm in a C-plugin.
For example, you could write a PHP extension if you plan to use PHP, or a Ruby extension if you plan to use Ruby / Ruby on Rails, etc.
That way, you can keep your streamline code simple and easy to maintain (it might be way harder to handle request from C rather than from PHP), while having a strong and solid background core (because it's compiled, and the compiler tells you what the issues are at compile time)