Pros
I love working at WayUp. Everyone on the team is ambitious and helps one another like a family would, the founders are smart and passionate, the mission is core to what we do, all of the managers are so dedicated, and the company is growing quickly. I have to disagree with the comments about this company being abnormally "young" (especially in startup terms), though I do think it's impressive how much WayUp gives its "young" people the opportunity to grow and learn more quickly than really any other company I've worked at before.
Cons
As someone on the more senior side of the company, I love working at WayUp because it's a hands-off environment where people can be entrepreneurial and make a huge impact. That being said, junior people (<5 years experience) seem to either love or hate it, given that this is not the kind of place (yet) where someone is going to tell you exactly what to do. Whether you want to call this "chaos" or just "a startup" is perspective. I think most people who have had a bad experience at WayUp were people who didn't like the constant change and lack of perfect structure. (To put the negativity in perspective - there was a contingency of people who were so negative that one admitted to a few employees that she posted twice on Glassdoor.)