Pluspunten
For a software engineer, Expedia is fairly unique among web companies. Because it was started in the mid nineties, it created it's own infrastructure rather than relying on off-the-shelf products as most sites do today. This means that as an engineer you have a much greater opportunity to work on both high and low level components. It also gives you a lot of freedom in terms of building new features into any of the core technologies. The developers in the company are overall very competent and good to work with. There's a wide variety of backgrounds and knowledge, so you're almost guaranteed to learn lots of new things through your daily interactions and projects. If you're on a good team, your experience will be very valuable and give you a leg up over the average developer with a similar number of years of experience. Expedia comes from a Microsoft background, so most of the things that make Microsoft a great place to work (flexible work hours, high standards, focus on technology) apply to Expedia as well. Currently, the office environment is great, but unfortunately that will soon be changing as the company moves to downtown Bellevue with a much more traditional cubicle environment. Being in the travel industry is great for an engineer. The industry is extremely complicated, and so the opportunites for trying to make sense of the ever changing industry are constant. You'll gain a ton of insight into the inner workings of the airlines, hotels and distribution systems that will help in your personal travels as well. Expedia also offers great travel benefits including wholesale prices on hotels and travel agent rates on a variety of products. Expedia is a generally admired company, so you can feel proud every time you tell someone that you work there. Many people will say "dot com!" after you mention it, which just goes to show how successful that marketing campaign is. The company in general is also doing very well, and has proven it can weather a recession and travel slump, so you don't need to worry about the company folding any time soon.
Minpunten
You need to be really careful about which development team you end up on. Some teams are filled with rockstars and have excellent management while others are almost completely filled with new people and have very weak management teams. Your experience will vary drastically depending on which type of team you end up on. Overall, most the engineering teams have far too much middle management, and that management tends to be out of touch with what's really going on with the individual developers and technology. There are teams where this is not the case at all, so again be very careful which kind of team you're interviewing for. When you have an interview with the hiring manager, ask them specific questions about the technology and how much they're involved in things like design and code reviews. If the manager doesn't seem involved, ask your recruiter if you can interview with another team. Another thing to watch out for is that senior management has been obsessed with rearchitecting the platform for the last three years. There have been many projects and most have been complete failures. There are some pretty major rearchitecture projects going on right now, and you want to stay as far away from these as possible. If history repeats itself, these projects will fizzle out as have all the previous ones, and you'll be left with nothing to show for all your efforts. Overall, I still think it's a great place to work, but just be very careful you end up on a good team. Ask tons of questions, and really interview the team. Plus, it makes you look good in the interview.