How can Ulreal Lumen do global illumination in real time?

I don’t understand. Isn’t a magic, right? How it be possible? In real time? In Eevee, even enabling soft shadow makes the movement in viewport slow. If I see Lumen’s illumination in the video below not it draws realistic shadows from global illumination like 60fps.

Lumens GI solution uses a highly optimized software raytracer and other techniques. You can read up about it here: