Pros
Best company in defense, hands down Really care about their engineers: Everyone wants you to get your masters (fully company paid), insane benefits (essentially a 10% 401k match that vests IMMEDIATELY, essentially 4 weeks PTO, etc), top pay for any STEM field outside of software (and even then, only tech companies are going to pay you more for software, smaller ones will not), 4 days a week/10 hour day schedule means you get 3 day weekends every week (you honestly forget about work completely after 3 days so its a great reset), you (sometimes) get to work on cool things, solid career define career paths with a huge push to let you try everything and find mentors, you get to help defend the greatest country in the world I personally had to leave due to family reasons but would definitely be open to come back one day.
Cons
4/10 (or even 9/80 as the rest of the defense is) is a double edged sword: it's great that you have a consistent schedule and work hours, but you need to keep track of your work down to 6 minute increments. What this means you will basically always work 40 hours (overtime only when close to deadlines) so it's more relaxed than other industries but it also means you can't just go home early on some days (you'll need to use PTO to do so). And again, you gotta keep track of your time which is tedious and annoying to do Because it's nearly always classified work, you gotta work in classified labs which means no phones and a bunch of rules and regulations The ultimate objective (protecting the US) is awesome, but your direct work actually can be pretty mundane and boring at times. You need to put the time and effort in and prove yourself (and wait for new contracts) to get placed on the really cool work (but you could argue any large company will be like this) Defense can be pretty behind compared to industry standards, especially in software (BUT Lockheed is actually more modern than other defense companies haha). An aerospace/mechanical engineer will be doing top of the line work, electrical engineer maybe, but software will most likely not (it is there but its in R&D and you gotta prove yourself to be placed on that)