I co-oped for Facebook twice: first time in Summer 2015, and second time at Instagram in Winter 2016. Both times I had excellent mentors, and who coached me during my term. Facebook really does not differentiate between interns and full-times, so the work you get to do will be real and meaningful. They are also really flexible, and try to accommodate to your interests; I was initially assigned an Android project, since my resume has a lot of Android experience. However, I really wanted to learn something new, and my manager was able to accommodate to my learning needs. The corporate housing is luxurious and EVERYTHING at work is free!!!!! (Food, tech, snacks, etc...) The team and managers really try to ensure you have a good work-life balance, and encourage you to have fun at the campus arcade and bouldering rock! However, Facebook does move fast, and it can get busy at times. I would 100% recommend working at Facebook to everyone!