TikTok Machine Learning Engineer interview questions

First call with a recruiter, then a technical round with a machine learning engineer. I did not get past this so not sure what happens after. I could already tell things were not going well for me after I replied to the interviewer's "ni hao" with "hello", as he seemed visibly upset I couldn't speak Mandarin. It was a 1 hour interview that was supposed to be a 1:1 split between discussing previous work experience and solving a coding problem. However, the interviewer interrogated me for 40 minutes on my resume, and only left me with 15 minutes for the coding exercise, and it was a Leetcode hard question. I managed to solve it optimally, answer follow up question on the approach but then got rejected