Pros
Everyone loves working for Alaska Airlines. There is a lot of pride for the company. The flight benefit is amazing, however you should realize that most of the flights are full and utilizing (even the free confirmed seats they give you) is relatively hard.
Cons
For a software developer, I don't recommend Alaska as a place to work. They work in a style called "Mob programming" where a group of 3 to 5 to 8 people work together on a TV with a single keyboard\mouse. You end up spending most of your day watching other people code. I enjoy pair programming, but this is exactly as terrible as it sounds. As for the management, they are all great at a personal level. However, the survey results that have been taken over the last couple of years has been declining and when I left it was not in an upward trajectory. I left because of management. If you are a solid developer, you do not want to work here. It will likely be detrimental to your career and you will find most of the time you are frustrated. If you are a software developer that tends to struggle, you will probably find working here to be one of the best places to work. It's odd. But that is the environment the managers has created. Mobbing is not for developers who are good at what they do.