The author seems to be experimenting in UE4 or UE5 (material graph shown in screenshot), but the examples are displayed in sharedtoy embeds? I'm wondering, is there a direct way to save UE4 material shader to shadertoy or some easy conversion tool? Otherwise it would have taken eons to produce this page...
Most of the effects on the page are only a couple of lines it seems so maybe he did just rewrite them all? I do wonder why he bothered with UE material graphs if he's this proficient at shaders anyway.