Found at Reddit's "Oddly Satisfying" forum, this is, indeed, satisfying to watch on a loop. It's mesmerizing, even. I searched around online and found out that the video features "Kostya," who goes by "High Diver Fly" on his social media accounts. On his Instagram he describes himself as a "super fly slide instructor, professional high diver and artist, and flyboard rider." He also posted a similar video showing a slide/dive that is part of a "superfly competition," which seems to involve diving off giant water slides. These videos seem to be filmed at Blue Tree resort on Phuket, Thaliand, and Kostya shouts out to photographer Edwar Herreno who filmed at least one of the videos. Kostya also has a TikTok (there, he describes himself as a super fly slide diver, performer, high diver, student diver and creator of show) where he shares lots more videos of folks doing wild and impressive things on the giant waterslide.