Big corporation, but you will have options.
Pros
Stable, benefits are (still, used to be even better) very good for people with families, many projects company is working on, so you can change things up without leaving the company
Cons
Company is huge and has many old corporate culture pieces in place, hard to stand out as an individual contributor. Review system used to be very contradictive, on words promoting collaboration and teamwork while in fact pitting you against your peers. It changes now, but too soon to tell if it's a new approach for real. Many things depend on your manager. Forget about work-life balance if you want to advance quicker than average. The more time you spend here the more you get stuck with MS technologies, which doesn't help much when you try to find similar class employers outside of MS.