I was playing on faceit and a guy( as*hole) was hacking, I send him a friend request and talked a little with him, it seems he uses an external cheating device, I was like wot? wtf is that, did a little research and it seems that it's a external way of cheating, cheat running outside of your pc...
A chinese amateour programmer made a cheat that can bypass the faceit AC client.
It's not very popular so it's perfect, that means not a lot of people will use it and the chances of being detected are lower.
Search on youtube exactly this: CS GO FaceIT Hack Bypass FaceIT AntiCheat Client 27$...