BitCoin is basically a digital ledger system, allowing for keeping transactions based upon cryptographic signatures in a decentralised database, ensuring the transaction was initiated by the person owning the private key. From a philosophical point of view, it’s simply authentication and authorisation based upon a private asymmetric key, period! What if I told you the same idea could easily be transferred to code in general. As in, keeping a ledger of invocations towards some HTTP endpoint, where the client decides what code the server should execute? The obvious example can be found below.
You’d have to be pretty stupid to not see the use case for the above snippet, especially considering it’s arguably (probably) the foundation of Revolut, a FinTech company, threatening to driver every single European bank out of business these days.