Pros
Snapchat has been the best experience of my professional career thus far. It is a true start-up, but without the risks. No job is too small or too large, and the amount of impact and influence you have in your role (whether you're an intern or an exec) is infinite. It's a collaborative and friendly environment, and the organization truly values and invests in the individuals. The work is fast paced and challenging and you're surrounded by the most intelligent individuals on a daily basis. If you're looking for growth and excitement, you will find it at Snapchat.
Cons
Hours can be long and the workload can be heavy. I don't necessarily see this as a con, however, as the growth potential as an individual due to these two factors is bigger than I've seen at most companies. Also note that Snapchat is not the kind of place for someone looking for frills and perks. It's a place to get your hands dirty and there are times where you might be working on projects outside of your day-to-day responsibilities. For some, like myself, I love this. For others, this can be frustrating and if you're the type of person that's looking for routine and predictability, this place probably isn't for you. Snapchat requires flexibility and a team oriented mentality.