Bad experience.
It was totally wasting my time. Try to avoid any in person interview with this firm.
They asked for an in person interview.
When I arrived the reception on the ground floor, the staff said the firm cannot locate the interviewer and asked me to wait nearly 20 minutes before I could access to the firm lobby.
Then the interview took place in the office area instead of the external meeting room. The interview only took around 20 minutes.
The interviewer was apparently not interested in the interview.
To the interviewer at this company, if you only want to schedule some interviews to waste candidates' time, please arrange it online, don't waste our annual leave.