Does anybody have insight into how big UI changes like this get made at large tech companies? (e.g. Airbnb, Dropbox, Pinterest, etc.)

They're obviously doing A/B tests to figure out which page converts better. But where does qualitative UX research fit in? Is it in the initial concept stages, in the late stages as validation, both, or not at all?

If there are early stage startups in the area (or at the university), offer to help them with design projects for free! Early stage companies always have a need for that kind of stuff, whether it's redesigning a logo, landing page, or some clunky interaction on their site.

Looks great! And congrats on the successful raise.