Vantaggi
Epam is partnered with one of the big 3 cloud services providers (Google). Epam in Japan was founded because of that one contract - to provide support for Google Cloud in multiple languages - Japanese, Korean and Chinese. That said, its a great place to gain experience with Google Cloud; its a good career jumpstart to be a Cloud Engineer. The work environment is very globalized with many different nationalities. This is uncommon in Japan and definitely makes a global work environment. It is definitely not Japanese-style in terms of management. If you want a gaishiki-kei (foreign) company based in Japan, this is a good place to be.
Svantaggi
The company is struggling to gain clients in Japan. This is also partly due to management obsessed with the Epam brand - client must be big, must be a big contract and must be in line with Epam's software engineering heritage. The other part of the issue is management themselves - too political, seeing how the Google project is run. There are people who are vying for power at all cost and it is getting in the way of things.