Vodafone Graduate Technology interview questions

I applied as part of a fast-track interview process. It was for their 'Wonder Women in Tech' day, and we were to be interviewed F2F for the grad scheme on the day. The day consisted of female speakers who had worked in tech, talking about their experiences and tips, and answering our questions. It was really informative. Then we had a group challenge where we had to come up with an innovative, technical solution to reducing gender biases in the workplace. We then had to present our solution. This was a really fun challenge, and our team won. None of this however, was part of the application process. We weren't being assessed on this, it was just a part of the day's event. We then were halved, with one half being interviewed and the other half being given a chance to network with current graduates. Then the halves would switch when interviews were completed. All the girls were taken into a small room where interviewers were separated by panels/boards, so it was quite noisy as many interviews were happening at once, in the same room. It all seemed really informal and laid back. I however, was taken to a completely different room, separate from all the other girls, with another interviewer. My interview was very formal and technical, which was incredibly unfair, considering all the other girls had a more laid back, chill experience. My interviewer really grilled me when she really didn't need to. She had a set of questions, but chose to unnecessarily grill me on one particular technology for some reason. She claimed to have no technical knowledge, which I absolutely don't believe. After having spoken to other girls when my interview was over, they all said their interviews were chilled, laid-back, and not that technical. How very unfair. Not fair of Vodafone to give me a much harder interview than others. If I had been interviewed the same way as all the other girls, I really would have stood a good chance. Very very unfair process from Vodafone.