[jknightco]

Execution time isn't the only cost in building software however. Building a web application in C may be "cheap" in regards to scaling performance, but it would sure as hell increase development costs a ton.

I think what Github has done is exactly what you're supposed to do: build your product on a platform that allows for quick growth and easy iteration, identify the slow parts, then swap those out for faster "gears" as you said.

Edit: I find it rather humorous that you find algorithmic research to be a magic bullet, but believe switching platforms to be a viable solution when faced with a bottleneck. I believe you have that backwards :)

[oinksoft]

I don't think parent is suggesting the whole website be written in C. I think parent sees the CS focus as a sideshow, and that a C version of the "escaper," even if not designed ideally, would still smoke the Ruby version that was acting as a bottleneck.

[jknightco]

"...parent sees the CS focus as a sideshow..."

My point is that the CS is never a sideshow. Improvements gained from changes in algorithmic complexity vastly outpace improvements gained from switching languages/platforms.

Worry about your algorithm first and your platform second.