Pros
Proofpoint has been a fun and fast-paced place to work. The account teams work well together, but I've never worked this hard in my life. The core products are very solid and the emerging technologies are worth a look. Most of the accounts already own the flagship email security product, and that relationship helps when trying to expand the products.
Cons
Not enough accounts! You will burn hours working with your AE trying to figure out how to sell the additional products into a limited set of accounts. Sales management is always tracking the pipeline and asking us why we never have enough opportunities; while giving you fewer accounts every year. It's too hard for engineers to make money, especially when considering how hard we work. It feels a lot like a 20-year-old start-up with its poor back-office processes, too many document repositories, and every quote needing to be approved by the CFO (massive bottleneck). The company is cheap to a fault, I'm surprised we don't have to buy our laptops. The lab facilities are running on antiquated hardware using OVIRT for virtualization (because free is the best). If you need to do any testing, build it in AWS or another cloud-hosting service, but you can expect to foot the bill. Lastly, you can't rely on the customer support process and often need to fix the issues or nudge support to respond.