BT Group Campaign Analyst interview questions

I've been involved in a lot of hiring processes and this one was by far the worst experience so far. First of all, there was no structure in the process, like you would expect from any large company. There was 1 phone screening call with a recruiter, then another video interview (1-hour) with the hiring manager + one consultant (a contractor if I am not wrong) and then the last step was to have another 1-hour session with the same 2 people (hiring manager+contractor). As any experienced hiring manager can confirm, it's just extremely poor experience to have interview with the same person(s) more than once. If he needs more time, then just extend the 1st interview; if he needs a second time to decide whether you are a good fit or not, then this person is just a poor interviewer and he should never be involved in the process. The amazing part was that for the 2nd (final) interview they asked me to present a previous analysis that I did in my previous companies. I responded that they cannot really ask me to present anything from my previous work experience, as all analysis/findings were confidential and they confirmed that they would be happy for me to use dummy data. So I just pulled data from Kaggle and presented the analysis/findings. Not only they didn't have any idea what Kaggle is (we are talking about people who claim to be analytics professionals/managers) but they also didn't have any clue how A/B testing works in large companies. In the end, they were very polite and promised that they will provide feedback after couple days. We are talking about a role which was advertised as the most Senior sole contributor role of the team and the salary was relatively high. But they were asking extremely basic analytics questions that any graduate could answer straight out from uni. I waited for more than 1 month and nobody contacted me for any update. I sent an e-mail to ask for some feedback and the hr person just replied to apologize and confirm that they finally decided not to proceed (With 0 feedback). Just terrible experience and total waste of time. I wouldn't advice anyone to apply to this company until they modernize their hiring processes.