Rakuten Software Developer interview questions

The codility is easy. If you know your math, you can pass the exam. I am not a fan of recorded video interview. You are asked 5 general questions. For me, it's hard to answer, not because I didn't know what to say, but because I was seeing myself in the screen. It felt too unreal, unnatural, compared to when you are actually talking to the actual person. So I ended up talking only a bit for each question. I didn't get through the skype. So I am not sure where I actually failed. At least I know I passed the exam. But for video interview? I really hope it will be an actual live interview to make it more realistic and engaging.

What is your most proficient language