I have long been under the assumption that bitcoin was just a "protocol" or a "contract“. Different nodes run their own implementation, on different hardwares. Some are efficient, some not, and they have to agree to the bitcoin protocol to function in this ecosystem.
But I found out there is actually a centralized bitcoin code base that’s frequently updated! How do they even ensure that every nodes update to the newest code? And how do they ensure that the code compiles for every single hardware?