Prós
You'll work on technology which has the potential to change how the world deals with antibiotic resistance and the future of healthcare. The people are fun to work with and are passionate about the mission and care about each other. People have real friendships outside of the office. There's a lot of opportunity for challenging yourself and growing as long as you're willing to take that on yourself.
Contras
I don't consider this a con, per se, but it is a startup which sometimes means priorities change quickly, there's not always a lot of explicit direction, and there can be long hours or long weeks, but those can be offset with PTO. That said, if you enjoy getting to create your own path, having autonomy, and building something new, it's a blast.