Sandia works hard to keep talent and find the right position foe you. After you are in there are even more opportunities for growth and new areas to work in. I have met some of the hardest working and smartest people I know from my time there.
Cons
It can be hard to get hired the first time. At various times an archaic HR system that overvalued Bachelor's degree GPA over knowledge and skills caused me to miss bringing in new talent.