It's actually a pre-eliminary interview process. First they asked us to present something about random topic for bout two minutes, the topic is like: what do you think if your car broke down in the middle of nowhere, what do you think of women as an engineer, etc. The next part is the Skills test, the subjects are maths and basic physics (electrik, mechanics). then the third part is group discussion and HR interview. If you passed, you'll face the user interview and medical check up.

3 Mins Interview to "Vibe Check" and test your english, then HR Interview, then User Interview. In my opinion, it's better to be as natural as possible, but prepare your technical knowledge and professional attitude.