Hi, thanks for the kind words! I'm Tom, co-founder of Fast.io. We started with a basic Bootstrap template and then heavily customized it (hand-coded). I'm really glad you like it! We've agonized over the messaging, illustrations, and animation quite a bit. I'm sure we still have a lot we can still improve but we're really proud of how it came out.

Actually, I should mention that it was really interesting to build our homepage on our own platform. We started out roughing it in really quickly in a shared Google Drive folder that deployed to a public URL (https://fastdev.imfast.io for example) then, once we started to have more people working on it and required version control, we switched the site over to GitHub and started deploying there. It's a little mind-bending to just hit save and watch a public site update.