Pretty much everything else. Management is awful. Awful, awful, awful. Here are some examples:
1) My manager was supposed to approve a coworkers promotion, she received confirmation in her review that she had received said promotion but never received her raise. Turns out the manager never approved it and lied to the employee every week saying it was getting corrected, going as far as forging a compensation sheet to cover up her mistake.
2) After the aforementioned manager was fired it was up to the director to schedule our reviews, which going into the last week before the deadline, we still had not had. We asked everyday for our reviews, we wanted to at least know what our compensation would be before any salary changes took effect. Instead of ever getting our reviews, 6/9 of the women on my team were pulled into a meeting with managers from other departments where we were tersely informed that our team would be split up, our remaining 3 friends and coworkers had been laid off (after a combined 12 years of tenure), these were our new managers effective immediately, and we would be meeting with them right aftewards (so we could not see our friends on their way out). The girls laid off were so graciously informed they could have their things mailed to them. It stung having this happen to an all-female team of capable women at the hands of one man who clearly derelict in his duties, did not want to clean up the mess he allowed to pile up.
3) Another coworker met with her manager directly after reviews were submitted so she could work on any opportunity areas before her review meeting in 2 months, but all of her feedback was positive. Two weeks later her manager lets her know that he "heard back on reviews and she may not be to happy about it." He let her know that upper level management wanted a bell curve so they adjusted everyone's number scores and gave the reviews back to middle management to rewrite to reflect the new scores. They bumped her down to inconsistent performance and therefore made her ineligible for a well deserved merit raise.
4) One time management pulled the entire sales team into a meeting for a "Pizza Party" from there in front of everyone, they laid off 40 people.
5) You're not supposed to be eligible for a review unless you have been at the company at least two months (used to be 6 but it's as if the want to fire the people they hire). A co-worker of mine had been working there for two weeks before he received his review, which was not favorable (I guess you're supposed to be an expert on the systems of a 10,000 person company after 10 business days??) Anyways, they put him on a performance improvement plan after his formal review and let him go two weeks later.
If you join Wayfair, expect to walk by people crying in conference rooms, expect to never a relationship with your manager (it's hard when you're bounced around all of the time, I had 8 in three years and narrowly escaped a 9th), expect for upper level management to never know your name or what you do, expect the people you work with to constantly change (and not because they "move fast, break things," but because the average tenure is probably 8 months"), and above all expect that illusion of a fun environment to be shattered. This place is not a start up which they want you to believe, they are very corporate but don't want to tell people that. And I guess they shouldn't because the place is way to disorganized to resemble any successful corporations.
If you end up here in desperation, at least try to keep your eyes peeled on the excessively unethical practices on the company and not sip the kool-aid too much