Pros
Everyone is given a lot of responsibility and ownership over their projects from day one, even junior people. You can work from home one day per week. They pay well. If you work overtime the pay can be REALLY good. Good 401k plan with 4% match. Cool office with a fully stocked fridge. Everyone gets a new MacBook pro, dual monitors, a standing desk, nice chairs, and any ergonomic equipment you need. There's a gym next door and FullStack pays for 50% of the membership fees. The hours are somewhat flexible. You get to work on cool projects for impressive clients. They work with a lot of cutting edge technologies. They expect you to self manage, so as long as your project is going well, you're given a lot of independence. The managers really care about the team and conduct surveys of employees to make sure everyone is happy on a regular basis. There are a lot of really talented developers here...and everyone is constantly getting better. You get to build complex apps from the ground up, so everyone is regularly learning a ton, and learning new technologies, techniques, etc. FullStack is the opposite of being a "cog in a wheel"....everyone has a direct impact on their projects.
Cons
Consulting is hard work and can be challenging. Tracking billable hours isn't a lot of fun, but it's expected when you're a consultant. The company is growing fast, so there’s not as much structure as larger / more mature companies. You have to be OK with a dynamic environment and a hands off management style.