The whole process was very fast. I had the on-site interview in the week following the phone interview. During the on-site interview, I was interviewed by three employees and one hiring manager. None of them asked me anything about my past experiences and they didn't even ask about my story, like "tell me about yourself". It seems that they didn't care to learn about me but all they cared about is my motivation to work at their company. I was asked by each of them the question "why do you want to work at Flexport?" and two of them asked me whether I would be satisfied with what the role does on a daily basis (which is basically manually entering commercial invoice into their system). The hiring manager even listed out the career growth path at the company and literally asked me if I would be satisfied with the advancement to a Global Operation Associate in the future. In order to check if I would stay long with the company and whether the next career role fits me, he asked about my future plans. So based on my experiences and the questions they asked during the interviews, I can tell that they are not looking for "real talent" who has a passion for the company and the industry but someone who is happy with manually entering data for long hours and will stay and be glad with the career arrangement by the management. I'm very disappointed not about the hiring process but about their mentality.
For HR, think hard about the interview questions cause it well reflects the company's culture and the quality of employees. I understand it's a startup company and employees are very proud of their culture, but it doesn't mean to be so "casual" and "random" in everything.
For future candidates, there are two case interviews. One is a business scenario they encounter very often. Another one is more math related. Both cases are extremely easy, so don't panic.