Pros
If you are looking to start your career it's an excellent place - epam will teach you from almost zero-knowledge-no-experience to good-knowledge-production-experience. There are many mentoring, courses, and programs to improve your skills throughout your career.
Cons
As far as I can see, payment is lower than in other companies on the market. Lead or Senior developers may be paid about the same as middle developers in other companies. While IT payment is good overall, knowing someone paid more for less work is not motivating. At some point in your career, you become a manager instead of a developer - it happens on the senior/lead level, and sometimes even on the middle level. It may be what you want, but in most cases - it's not, people prefer to do development, and now they had to do half or more of their time in managerial work. This is not great at all. Be aware that project start and go, so you may change several projects per year-two, but if you are lucky you may stick to one for a long time. It's really hard to predict where you will be next year. You still will be paid and all, but changing projects often may be not what you want. Benefits mediocre. Free coffee/tea in the office, some discounts on sports. You won't get Newe Year gift, payed lunches etc. It may be not critical, but other IT companies provides those.