On the other hand, people with that sort of experience tend to have the worst instincts when it comes to actual maintenance and long-term development of projects. They're great at starting projects, and fast too, but rarely considers the design carefully enough so you don't need a full rewrite once every year just to continue being able to add features. Slow is fast in those cases, and the people who are experts in "greenfield SaaS MVP launches" basically operate with short-term expedience traded for long-term maintainability.

Not to say they cannot learn that, but worth being aware if you're building something long-term and does hiring for that sort of project, to be upfront that the development process will likely be very different compared to what they're used to.