[jamesfinlayson]

> If you have a fast design/architecture, you may never need to optimise the code at all. But the flip side is that with a bad design or bad architecture optimising the implementation won't save you. With a sufficiently bad architecture starting again is the only reasonable choice.

Yep, completely agree. I worked at a company with a poorly architected high-throughput system that was written in Perl. It got to a point where no more optimisations could make it scale, so it was rewritten. Of course the rewrite in a "faster language" was touted as the reason for its success but the truth was the new architecture didn't pound the database anywhere near as much.