Avantages
The company is objective, unemotional and focussed. For a certain type of old-school mathematician nerd (not the new-age script-kiddies), this can be a good thing. There are no company wide memos on "culture" or "grand visions". Everything you do has an objective, and a measurable, well-defined outcome. You know why you're doing something and that helps you make decisions faster, easier and more efficiently. The company is growing, aggressive and I believe the only company able to withstand Apple. The company genuinely cares about customers - that's not rhetoric. You can find an Amazon engineer at 3:00am in the morning, shake them out of deep sleep, drug them and ask them why a certain decision was made. Whether they're on-guard or off-guard, the answer won't change. If something impacts customers in a positive way, it will be done.
Inconvénients
The above pro can become a minor con since there is little to non-existent romanticism about any type of work. The biggest con is facilities - I came from a company with lots of facilities, on-campus laundry, etc., so I was used to convenient parking and a lot of campus-wide services which was a mild annoyance to me for a few months. The hours aren't quite flexible, so it gets difficult to manage your time if you have to visit other businesses during business hours only.