Vantaggi
Amazon gives everyone a chance. They're a cheap employer (codeword: frugal), and treat their people like cogs in the machinery (no, really - codeword: fungible) but at least they haven't developed an elitist culture. On the contrary, they do promote from within - if you play by the rules you can really work your way up like in few other places, and that's great, but if you take that route you'll be paid less than your peers coming from the outside or if you climb the ladder too high, you'll be under enormous pressure to deliver and/or at a constant risk of downgrade during next performance review. Amazon is a place where scale happens and the law of large numbers applies; it's a big plus if you're into that sort of thing. There are good chances you'll find sharp people on your team, but if they're really good, they won't stay too long!
Svantaggi
If you're worried that they'll overinvest in you, you can stop worrying now. There is zero-regard for wellbeing of employees and any solution to any problem must not involve spendings! One time a water-cooler was busted for weeks, and someone opened a ticket to complain about it. He heard "this is not Google" in response. They offer decent salary, but when you realize the expectation of unpaid afterhours that you have to put in not to fall behind, it hits you that you would've made more per hour as a pizzamaker. It's only when your manager starts keeping you occupied with paperpushing and busywork tasks, this is when you realize how deeply fulfilling becoming a pizzamaker would've been. While we're at it, micromanagement eats this place from within. Software devs are made to commit to unrealistic deadlines while executing the project exactly the way the czar wants it. But it can always be worse. Under a mercenary manager, micromanagement will be the least of your worries. Try to come up with ideas they don't like and you must produce data to support your case. When you put it together, they'll make a straw man out of your data and set it on fire right in front of you. Of course, the same data-driven diligence does not apply the other way. Those who won't comply and won't become obedient YES-men don't have a bright future ahead. I've watched a colleague being bullied out of the job. It's really sad that company's culture is a breeding ground for such managers and that, at the end of the day, they are perceived as successful.