In total 4 rounds, In short words: don't waste your time here, I interviewed over 10 companies in 1 month, and this is the most unprofessional one from the beginning, I can't believe such a company culture can exist in HK.
1 round hr 30 mins call, are you basic info, then ask you what is Kafka,
2 round, coding test, you can find the problem and reference on GitHub if you know how to search, quite general but seems it's not related to the following test.
3 round, interview with two engineers, it's strange they closed the camera, and asked some questions unrelated to the CV and job description, one person kept asking something that came up in his mind, I felt like he also didn't know what he was asking, unprofessional,
4 round, interview with tech manager, care about the midnight operation and on-call experience, seems smooth and said will give feedback in two days.
the funny part is here, after the final round with tech manager, the HR is missing, yes, just disappeared.