Pros
Mercury Systems has a fantastic engineering team that I am proud to be a part of. Plenty of Mercury engineers have been in the industry for decades, so there is no shortage of experience. The company culture reflects this older workforce. I have learned more about property, taxes, politics, and investing from Mercury employees than any other medium. From a new-employee perspective, this is the place you want to be if you want to kick-start your career. I am by no means some superstar engineer. However, the experience I have gained from working at Mercury has really filled in a lot of the gaps in my knowledge and given me confidence in my work. Even from a business perspective, Mercury is leading the industry in growth, and has only accelerated after their recent deal with Microsemi. Overall Mercury is well-prepared for the future, and they will be looking for plenty of younger engineers as well.
Cons
Working in the engineering group at Mercury, it feels like there is a real disconnect between management and engineering. This is probably an issue everywhere that gets swept under the rug, but it felt more prevalent at Mercury than any other companies I have worked for. There is also a lack of formal training in the company, and the little training that is available tends to be provided for managers. It's not that you won't learn new skills here, you certainly will, it's just that there's no real learning program setup for the senior engineers of the company to keep up with newer engineering tools and concepts.