1st phone call with HR. Then, I was constantly contacted by HR on Whatsapp, no matter what time and day (even though they had my email), which I found really unprofessional. 2nd online interview with hiring manager. 3rd interview has been in person and it took almost 2 hours, half an hour with HR and more than one hour to present a business case to the Hiring Manager. Important to be mentioned, that the business case included also SQL and Machine Learning questions. I asked HR if those were in scope and I was told that EVERYTHING was in scope. After finishing with SQL I asked to provide the data for the Machine Learning part and only at that point HR told me to actually ignore that part because it was not in scope. I should have understood that they like to waste your time. 4th online interview with the data director. After receiving positive feedback from the 3rd and 4th interview, I was eventually told that the scope of the role has changed, so they had to restart again with the hiring process. I asked if they could provide a more detailed explanation but then I have been ghosted. I sent more than one email and all of them have been ignored. After all the time and effort spent on the hiring process, I felt really disappointed and I would suggest to not lose your time with this company.