I used FastTrack in the early days and loved the product.
Problem was their question bank was too small so it was easy for anyone motivated to cheat. I spent under an hour reading reviews of what questions were asked, prepared solutions for those questions, and then in the interview there were no surprises. I merely regurgitated my prepared solutions. One of them was making a tic tac toe game.
If employers knew how easy it was to pass the Triplebyte exam then I wonder how many would have allowed candidates to skip to onsite.