PayPal Data Science interview questions

I was contacted by a campus recruiter saying that a hiring manger would like to interview me for Data Scientist position (campus level). At the time of my scheduled interview, instead of the interviewer mentioned by the recruiter, I received a call from a hiring manager from some other team for an intern position. After this confusion, the actual hiring manager called in around 10 minutes late and sounded very unprepared/ uninterested to take the interview. He asked questions on technologies which he mentioned that are no longer used in the team anymore. Overall, it was a not positive experience definitely.

Had to submit a Codility test (an online coding exam). I was asked to print out a given sentence with each word backwards and to write a function that given an array prints out the max of differences you get from splitting the array into two sub arrays and subtracting their minma (on all possible divisions). Above functions need to work in O(n) time. Second stage was a frontal interview, personal and professional. I got two sheets describing a PayPal transactions - name, email, ip, sum, product and whatnot. I was asked to confirm or decline the transactions. After we had a discussion about what possible scenarios can make this a legitimate deal but still fail my criteria and the other way around. Third time II got a csv file describing multiple transactions (each deal structured as what II saw the second time) in addition each had a validity boolean field. I was asked to analyze the file using programming or other tools. Last interviews were with the team leader and HR.