After a lengthy time the 3rd party recruiter sent me in for application, I got an invite for a first interview with one day notice over teams with the department head, this went well enough and I was asked to come in on-site for second interview and with two team members for the technical portion and a personal focused interview by a member of HR. Again this was with one day notice, and I was told this was a final stage. However two days afterwards I was told the feedback was very positive, but they thought it would be "beneficial" for me to meet another manager and deliver a presentation. I told them this was fine, but I needed an answer for offer quickly afterwards, as I was holding an offer elsewhere. So I came in again for the third interview, delivered the presentation. Again i was told the feedback was very good. but they delayed making a decision. My recruiter kept chasing them on this, until randomly one evening almost a week after my third interview, I was told they were not going to go ahead with me, and gave no reason why. Truly the worst interview process I ever had in my whole career.