Pros
Every day you are challenged in different ways as the company and product continue to grow.
Teams and management are flat and transparent which makes cross-functional projects and task straight forward which is rare.
Everyone is easy to talk to in development and customer bugs and features are prioritized.
Lots of autonomy to tackle your work as needed to achieve the defined end goal.
It's generally a fun place to be, nice view, weekly office lunches, annual team camps, other occasional fun stuff just because...
Cons
Its a startup so on any given day you will have more than one hat on.
Teams are small and growing so ongoing peer development, training, hiring process debt is the name of the game at the moment in every department.
No one is going to tell you what to do (some love this, others just don't know what to do).