Overall great place, with downsides like any other company
Pros
Great lower level leadership (group leads/department managers, mostly smart engineers with people skills, interesting projects with the ability to cater your work to your interests, lots of opportunity for learning with an emphasis on collaboration, unique corporate structure where you can be working with different people on different projects so you aren’t pigeon holed into the same teams, greater flexibility than other defense contractors due to being a not-for-profit, employees are considered “individual contributors” where you are encouraged to really innovate, think about possible solutions, and try it out even if it doesn’t work, average benefits across industry.
Cons
New benefit changes have adversely affected those with long tenure, C suite has made decisions without fair warning to the rest of the company, there is a lack of trust and communication between the decision makers and other employees. You can always find better pay and benefits by switching companies, but I have found the work life balance and flexibility to be very good at MITRE which I would not trade in for higher pay, plus knowing it’s a not-for-profit and I’m doing influential work is worth it to me.