If you look at the list of pros, many of them could be cons for some people.
Owner makes no secret about the fact that it is ambitious and likes to move fast, which means you're going to work very hard. The good news is the work itself is rewarding -- it's not busy work or "tracking hours" type work, but meaningful, interesting initiatives that are changing people's lives.
For those who want a clock-in, clock-out / leave work-at-work type job, this will feel unreasonable. But for those who want more, who aspire to be great or work at truly great places (and I'm not talking about the fake award kind of great places), you will thrive here.
The conventional wisdom today is that we should give the bare minimum to our jobs; that time spent in our 'professional self' should be minimized. Owner defies that. They say, "we'll ask a lot of you, because we know you can do it... and you'll be blown away by what you can accomplish."
