How did you find out that it uses stuff from other websites? Reverse image search?
Something about the "skinny vector people" just seemed really boilerplate to me, along with telltale signs of "someone used a bootstrap-like framework" like the cards not having the same vertical height. Nothing on the page made it seem like it was actually designed for a dev-centric service, it all just looked like it was ripped off a generic dating template. So I just wanted to confirm that hunch.