Based on following the links in the video details, it looks like it's built around something called the OCTA metapixel [0][1][2].

Conceptually, I could see how once you have an "abstract programmable pixel" with mechanisms to change how they interact with each other, it becomes "straightforward", since you can abstract away the concept of a pixel and its interaction with neighbors.

[0] https://www.conwaylife.com/wiki/OTCA_metapixel

[1] https://otcametapixel.blogspot.com/2006/05/how-does-it-work....

[2] https://b3s23life.blogspot.com/2006_09_01_archive.html

You can think about it step-by-step: first you need some rectangular structure that has two well-defined states to represent your cells, then you think of how to implement periodic refresh and communication between neighboring cells, some gadgets for and/or gates, etc. As you have gliders, glider guns, and similar building blocks, it is not that difficult, given enough patience. Very nice to look at though :)

For more insight on designing GoL circuits: https://codegolf.stackexchange.com/a/111932

The hardware metaphor seems apt, as GoL has a speed of light & the parts operate concurrently

So not sure what you mean by reverse engineered, maybe you're getting hung up on Kolmogorov complexity being incomputable

Life is turing complete, so there was no need to “reverse engineer it”, they built a computer that is simply simulating life, in life.