1. The opportunity: In the featured Glassdoor review, any employee unhappiness is blamed on the "difficulty" adjusting to "restructuring" because of "recent acquisitions." I think it's true that growing pains from acquisitions are to blame, but the problem is that the growth didn't benefit employees. Expectations increased exponentially, but there was no reward for all the effort. Many of us were hired young for low (but fair at time of hiring) salaries that despite promises of raises and new titles, didn't adjust to market rate after putting in year(s) of high quality work. Post acquisition there were new business initiatives that lead to 60+ hour work weeks causing bugs and rollbacks. Project management was bad and priorities would shift because of a lack of communication between upper management and engineering. Here's a fun scenario: You're working on a project. Midday you're pulled into a meeting and told to stop everything because there's a high priority new project that you'll need to plan, finish, test and deploy by the end of the month. You're told that there will be a lot of late nights on this extremely important project, but afterwards everything will calm down and if you prove yourself on this project, you can expect a raise. You get 3/4 of the way through the project, and then find out that the project was cancelled last week. Or maybe it's been de-prioritized for a new super important project that you'll get moved to later today. This happened more than once, lowering morale and trust in management.
2. The coworkers: There was a mass exodus in engineering. Some of the most talented people left during the same 6 month period because they were unhappy with the way things were going. Seeing friends leave for great opportunities (high paying jobs at major companies) makes you question why you're still there.
3. The benefits: Unlimited PTO means that you have to ask for the days you take off. If you take off an amount that's seen as "a lot" or you go on vacations "too often" you'll get side-eye for it and your work ethic will be questioned.
4. The events: Before going to event you had to look around and make sure other people in your department were going. There's a culture of it being good to be "too busy" to go. It's uncomfortable to walk out for a paint and wine event if you know the person next to you and your manager are staying to finish up some work.
5. The work-life balance: It's difficult to maintain the work expectations longterm without burnout.