A Book You Never Erase - the append-only ledger, reversals and derived balances
The log: append-only, ordered, kept, with “state = fold over the log” in its event-sourcing box. That board is about events in software. This lesson shows the same shape is what a money ledger has to be, and what you do when a line in it is wrong.
Education, not financial advice.
Before you start. From Every Litre Leaves One Tank and Enters Another - double-entry, normal balances and the trial balance: a ledger is accounts and entries, every transaction sums to zero, and the trial balance adds the book up as an alarm. From The Ledger Everyone Reads (event-driven & the log) (or Kafka 02: The Log if you came from From Scratch): a log is a list you only add to, and many readers read it at their own pace. This lesson needs nothing else.