[sirn]

I used to run an image board written in Python with around 15m PV/month on a Pentium 4 machine in 2004 or so. The first bottleneck I found was the database. Some query optimization and caching fixed it very quickly. It goes a really long way until Python become a bottleneck, of which can also be fixed relatively easily (image processing in my case, which is fixed by moving the whole thing to a worker).