Pros
You get to work for a very fast-paced company, where you could shape your role the way you desire as you will probably be building something new as opposed to filling a pre-existing role. Your sphere of influence will be big and you will often have access to talented peers and an incredibly approachable executive team, who commits to your development. People here are solving big problems with small experiments. Things you work on can scale fast such as figuring out how people will search online and bring the buy/sell experience in-person and local...a problem large retailers worth $ Trillions are trying to solve. You will have an authentic, relentless and visionary co-founder and CEO committed to make OfferUp a household name.
Cons
Processes feel a bit unsophisticated for the stage of the company, probably a symptom of hyper growth. Resources seem insufficient for all the OfferUp wants to accomplish which could frustrate those not willing to make the tough calls. Parking is limited and so are walking distance food options.