Amazon

Smart People. Barring the odd SDE/SDET, the vast majority of engineers at Amazon are really smart, motivated people who just get how things should be built.

You get to deal with really crazy problems of scale that few companies ever think about (except MS, Google, Apple and Facebook).

If you know how to fix something, you just go and fix it.

AWS documentation is excellent with well-defined and well thought-out APIs.

Huge fleet (of machines) at your command.

Agile and fast-moving with minimal bureaucracy.

Seattle is a beautiful city.

Great focus on the customer.

Company culture of frugality is sometimes taken to an extreme, where developers can't even get proper hardware to develop/test on.

Some Software Managers and Technical Program Managers don't necessarily meet the same quality bars that SDEs meet.

During peak times, long working hours are the norm.

On-call means that you can be paged at 3 AM to solve a problem on the website/backend. This depends heavily on which team you work on.

Lots of legacy code keeps breaking, resulting in people being paged frequently to fix problems. Teams that don't tackle technical debt mean that these problems will continue to plague certain teams in the company. Other teams manage to get this right, though.

Equip developers with the resources they need to succeed at times.