Rakuten work culture

​Anyone work as a software engineer at Rakuten? I'm looking for some inside info on a few things:

​Work Culture: What's it really like? Is it fast-paced, collaborative, more traditional?

​Tech Stack: What languages, frameworks, and cloud technologies are they using?

​Skill Development: Are there good opportunities to learn and grow? Any support for certifications or attending conferences?

​Perks: What are the best benefits and perks for software engineers?

​Any anonymous insights would be appreciated! Thanks!