Through this position introduced by a recruiter, she was very active in contacting me and the company, but the company wanted to have an interview with me, but he asked me to do a case study directly that he was too busy to have an interview with me. I used a full 2 ​​days to clean the data and find out the business problem, the data format is "01 02:52:12", and problems such as time zone. Based on such irregular data, I made a detailed analysis and report and gave suggestions. Finally, the feedback to me said that I did not give advice...