Terrible.
For foreigners it is impossible to get in kakao because they focus on language skills more than technical skills.
I passed the online test and all the technical rounds but they rejected me after the HR interview.
I applied online. The process took 2+ months. I interviewed at Kakao (Seoul) in May 2019
Interview
The first two processes were coding tests and the third was a video call. The questions were based on the problems of the coding test taken previously. The interview was 1:2.
Interview questions [1]
Question 1
Explain the question and solution of the previous coding test mathematically.