Pros: They try hard to have a good work culture with snacks, monthly team outings, tickets to sporting events, etc. The company is doing well and will probably...

Cons: The codebase is awful. There's 10-year-old ASP code, but the founders and senior employees don't seem to understand standard software development methods. Consequently, no one can take the time to do it properly. Anyone but senior engineers are basically code monkeys that spend 80% of their time dealing with existing code. The excuse is that they do things quickly "like a startup", except there's way too much traffic and complexity to the code to do things "like a startup". Also, no one seems to know the requirements, so you can't change any existing code for fear that you'll break something. The perks are good in theory, but snacks and one free drink a month isn't enough to make up for the unfulfilling work. Free event tickets are based on tenure with the company, so you have no hope of getting anything good until you've been there a few years. There is high turnover, with a lot of new engineers leaving within 6 months.

Pros: Many opportunities to learn new things for newbies and career growth for experienced persons.

Cons: Because of really fast growth, projects can be a little bit unstable. Sometimes you have to redo the same features because some requirements changed.

Pros: The company strikes a good balance between being serious professionals who are there to get a job done, and having values and policies in place to support good work-life balance. Most of the people there are good at what they do.

Cons: Leadership from the VP level up is prone to sudden moves, like department reorganizations, which don't seem to be motivated by any consistent theme. This happened around once per year during my 5 years working there and was very disruptive. The managers have a lot of power within their team, which makes for a highly variable experience for the people working at Wayfair. Your relationship with your manager and their competence at their job will have a huge impact on your career growth and happiness. Like in many tech companies, a small group of activist-minded employees have a disproportionate impact on all the other workers.