I started watching handmade hero 4 years ago. I think I've learned more watching handmade hero streams than attending computer science college :D
a year later i started working for my current employer (medical imagery and dentistry stuff) where i worked on a big C++ codebase, with OOP, heavy inheritance, and design patterns, the whole shabang. it was very hard to reason about, very slow to develop and compile, and very slow in runtime as well
I started introducing the things I've learned from handmade hero and fast forward a couple of years. now we have mostly C style codebase which compiles from scratch in 2 minutes instead of 35 minutes
I started to talk about what we did to some of my friends in other companies and they were impressed by the simplicity and effectiveness of this style and started to introduce it in their work, we also started to meetup in late 2018
here's a picture from one of the meetups