Lots of young people in the office and some teams have opportunities to work with senior government executives. The work helps benefit veterans, which is pretty cool. I believe Atlas hires "senior consultants" from other companies and gives them "manager" positions, so if you fall into that category Atlas is a great opportunity. I've noticed that if you are working below a manager or senior manager a lot of your experience will depend on that single person - work environment, experience, work-life balance, opportunities for advancement etc. There are some Managers at Atlas who do not have managerial skills and have no business being in charge of others but the company is growing so fast that they have low standards, in some cases. Most people are good, but if you're on a team with someone who isn't - and they are around - good luck to you!
Cons
Horrible benefits that dont represent industry norms - no 401k and bonus. Terrible HR in general. Their entire office is an "open environment" which can be really annoying, especially if your boss doesn't let you telework. Some people work in kitchens and closets, for example. Some managers dont have people skills and have no business being in charge of people or interacting in a business roles with clients. Atlas seems very cheap - a lot of employees dont even have phones or a phone number that isn't generic.