I once put together a blockchain-like solution that was actually running on top of a distributed database. Because it was using db's native replication, it was much faster and more efficient to distribute the blockchain among the participating nodes. There were some drawbacks too, for example the system required n/2+1 for quorum which is a bit more than than 51% for small clusters. So back to basics: I would start with the use case, problem to solve and then see if something like blockchain is the correct solution for the problem (as opposed to searching for some magic blockchain-like tech that is magically better than others for all types of problems)

I'm also curious about this. The pre-blockchain history of distributed ledgers sounds like it might be an important topic in this context: https://medium.com/blockstreethq/before-blockchain-there-was...

Actually there is one old distributed ledger I was told about when discussing what is money or a blockchain: the stone currency historically used on the Yap islands.

It started out by using some large distinctive stones and adding markings to them. Additional markings and additional stones could be added. A key property was that all the information was public and known to the islanders, so if someone were to fake a marking or forge a stone it would immediately be invalidated. The oral recounting of the stones was a literal gossip protocol.

As the story goes, a stone was lost to sea during a storm. Nothing changed as everyone remembered it and either already agreed what was on it, or came to consensus. The physical presence/existence of the stone wasn't needed at all.

[0] https://en.wikipedia.org/wiki/Rai_stones