NOTE: QuantiTech is now known as Axient, but it's the same company after a merger with another.
Everything else you can think of, including a lot of the people. You will not advance: being government contractors, we get a 0.5-3% cost of living increase each year. Nobody had ever been promoted in 35 years where I worked (on loan to Arnold AFB from 2018 to 2021). Demand high pay initially, you will not get it otherwise. I was 6 out of 8 people in a 30 person group that quit in a single year, with three others considering leaving after the New Year in 2022. A lot of the senior coworkers are Arnold AFB are highly toxic to deal with, and another QuantiTech coworker threatened me to my face and said he would get me fired. I reported it to HR and the Head of HR came up from Huntsville to "address the situation". After both the Head of HR and the Head of Personnel tried to convince me it was all simply a mistake and dismissed the case, my immediate supervisor came to me in private and told me someone did have it in for me, and had been anonymously reporting me for made-up infractions for over a year... a week after I started. Turnover rate is extremely high because the few senior personnel run the company like a fiefdom: if you're not a teacher's pet, you're out.
In my time there I worked with other parts of the base run by other contracting companies, and their personnel was extremely satisfied with my performance. I still have accolade letters from them. But the man who threatened me was a SME (subject matter expert) in optics. Tough luck for me.
And yes, over half the people who left were also people hired in the last 5 years. Don't expect a career at this company unless you can politik really well. It doesn't matter if you automate their systems and end up saving them $10,000 per employee per week through your work like I did. And that was just a streamlining of a data extraction process we performed roughly 250 times a day through our entire department!