You'll get a lot of ownership of a piece of their product right away and be expected to drive the development on your own. Lots of opportunities to go watch robots execute the software you've written which I found super exciting. Nimble definitely embraces the "move fast and break things" mantra in the best way
Also the office is in SoMa in San Francisco and is easy to commute to from most of SF by bike/bus/car which allows you to live in some beautiful neighborhoods
Kontras
Lots of folks work well over 40 hours a week (also kind of a pro; your coworkers will push you to be better and believe in the company's vision). Although honestly most people generally drew the line in the 50-60 hours a week range which still allows you to have a life outside of work.
Things can feel disorganized at times with priorities shifting radically week to week. Again, I think this is quite common with tech startups