An exciting, challenging, difficult place to work - worth it if you have the right fit, Avoid it if you don't!
Pros
Fast growth, smart people, new technology, legitimate focus on customers. a continual drive for innovation and "break-it" thinking to come up with new ways to serve customers and to be more efficient. usage of company products to run the company business - they "eat their own dog food." Their products are well done, and the customers genuinely love them - the annual user show is truly a love-in. The company is quickly building a real ecosystem, full of opportunities.
Cons
the environment can be political, you need to get the right people to support your initiatives and get your initiatives in alighment with the right people. there is definitely an arrogance that comes with the ongoing success - this leads to a "not invented here" syndrom, which means that you really need to pass on externally available solutions or vendors, they just won't fly. They haven't solved the customer support conundrum of "how many do we have to hire to take the customer's phone calls" - the products they design and delivery are generally excellent, but they don't "bake in" the customer support piece; they don't make the product managers take ownership of the successful customer adoption of the technology (through the complete lifecycle.) The internal systems to manage the company's processes are in a constant state of change and are still primitive and in start-up mode - the management is committed to solving this, but this can be a source of frustration.