Pretty sure I got a mock interview because the company had already picked someone

Recently interviewed on campus for a software engineering role at CrowdStrike, and I'm still trying to make sense of what happened.

I cleared two technical interview rounds, and both interviewers seemed genuinely impressed with my performance.

During my second interview, the interviewer even told me I had done an excellent job and that he was going to write excellent feedback. Before ending the call, he also said I should probably hear about the next round within two days.

Instead, I got rejected.

The part that really bothers me is the timeline. The candidate who eventually got selected had their interview two days before mine. By the time I was interviewing, they had apparently already moved that candidate into the final discussions. I obviously don't know exactly what was happening internally, but from the outside, it honestly felt like the decision had already been made before my interview even started, and I was just there to complete the process on paper.

What makes it even more frustrating is that I have a very strong profile. I'm not saying I'm entitled to an offer. There are always candidates who may be a better fit. But when both technical interviewers tell you that you performed really well, it's hard not to wonder what more you were supposed to do.

If the position was effectively filled, why continue interviewing people? Why tell candidates they did great and should expect to hear about the next round soon if the outcome was already decided?