Pros
GLG is by far the best company I've ever had the privilege to work for. Will Ballard, GLG's CTO, has created an environment of learning and sharing which certainly demonstrates the companies core values. In the time I've worked for GLG, I've learned more in my career than I have at an previous job. Personal development is encouraged and you'll get to the opportunity to work with incredibly intelligent colleagues. There isn't enough space provided for me to accurately communicate how great pair programming with the other members of my team is. Everyday I learn something new and have the opportunity to teach others, so each day I am rewarded. Every company needs to take notes on how GLG works, especially in the engineering department.
Cons
Each time I try to find something negative, I'm reminded by all the positives. Maybe 401K matching could be better given how much success the company has had in recent years. Perhaps a clearer pathway to how to achieve promotions would help retain long time employees. Overall pros far outweigh the cons.