Avantages
High pay for Seattle, which is not the cheapest but definitely not the most expensive city. As a software developer there can be a lot of leeway for technologies used. A single engineer can be involved in all aspects of product life cycle, there's little division of labor. UI, schema design, implementation, testing, maintenance... High hiring standards have paid off - your peers are very competent and many downright inspiring. The company really does make long-term strategic commitments and stick to them. Employees truly do frame meetings around "so how is this good for the customer?"
Inconvénients
Hours can be long. Pager-duty is a burden. (Both of these vary widely by group). Company-wide, there's not much room for promotion on the technical track (doesn't mean you can't get a raise or large RSU grant). Praise doesn't come easily. 401k match is a garbage 2% of salary. Absolutely no support for continuing education.