So if bitcoin was created in January 2009

And git was created in 2005

Does that mean that git was using blockchain technology before blockchain was cool?

git is a distributed system. blockchain is a distributed system. git is not based on blockchain.

No, because the git repo is hosted centrally, in a server. There's no consensus system needed

@SpectralKH Have you encountered the design philosophy of git? The whole point was that central servers would be theoretically unnecessary (each instance maintains a copy of the repo's state, rather than depending on a central state-holder, like CVS or SVN). The central git server is a use case, not a design feature, which approximates the consensus system (and is why almost no one uses truly decentralized decentralized version control).

@powerfulparadox How does that consensus system work?

@SpectralKH Each local git instance is a full repository and acts like it, so each developer can make changes anywhere in the codebase without direct reference to any other developers' changes. This is why centralized version control is a thing, because you can lock the parts of the codebase undergoing changes. Git makes you do conflict resolution through diff merges, and the common solution to make this straightforward for everyone is to work from a central, master repository (the git server) which holds a definitive master branch of the codebase. I consider this analogous to a consensus system, since conflicts are resolved and mitigated through reference to an agreed upon central master which has been built through decentralized work.

Hopefully I'm doing justice to both git and blockchain. I'm not really an expert in either, just someone who likes interesting architectures. @A-C-E raises an interesting comparison which might merit further consideration.

Of course, being architecturally similar does not imply the use of one technology by the other.

I just thought it was interesting how git’s way of creating a chain of commits using hashes and then including the past hash in the next commit etc was similar to how the bitcoin blockchain works by doing pretty much the same hash chain thing.

Isn’t that basically what a blockchain is? A chain made of chunks of data connected by the hash of the last chunk?