Pros
Whether you are in engineer or business department, you do get your hands on important tasks or projects earlier than what most other companies- simply because the employment turnover is very frequent. If you do get a chance to work with a solid team member, the chances are that he or she will be leaving the company soon or at least seriously considering exit plans.
Cons
Don't judge the book by its cover. While Rakuten promotes itself as "global" and "innovative" enterprise, it is quite the opposite if you stay away from the fact its official language has become English. - The entire full-time staffs were ordered to read the CEO's new book (which was expected to purchase or borrow on our own) and post what we've learned from it on the HR system. - Cost-cut everywhere. My former department's Online Travel Agency division) cellphones were all taken away and the entire salespeople had to use their personal phone for business purposes. The company also cut office supplies such as pens and notepads and expected us to bring our own. No air conditioning after 6pm, while most of the employees have to stay way longer to finish their tasks. - No bi-annual bonus is given unless you are employed on the day of the bonus. "Half" bonus for entry-level employees for the first year of employment. - Half of the bi-annual bonus is in "stock option", meaning that you have the right to purchase rakuten stock at a discounted price after at least 4 years of working there. It is rare to see any colleague who's been working there that long to begin with. - The company's business model is pretty much selling banner ads and its marketing is sending spam mails. It was very disappointing to realize it while they promote themselves as the Silicon Valley of Japan.