Spent months grinding. Accused of cheating for solving a problem too fast...

I spent months grinding Leetcode in preparation to jump ship from my current big tech company. I hated it the entire time, but I invested so much effort that I am able to immediately identify the optimal solution to most problems. At this point it is rare I see a problem that I haven't already solved multiple variations of before.

Just got out of an final round interview with a major company. The problem I received was a BFS + backtracking variation. Solved it a dozen times before. I explain the brute force solution, then the optimal solution, then write it while explaining each line. Took me under 15 minutes.

The interviewer says "so which AI tool are you using? I've never had a candidate solve this problem so quickly before." Obviously I deny, but we all know I am not getting an offer from this company.

What the fuck is the state of the interview process these days. Companies demand this insane Leetcode grind, and then when you actually do it, you get accused of cheating for being too fast? So demoralizing. Next time, I am going to intentionally make a mistake so that I can "find it" when I execute a test case.