Ah, personal finance tracking. One of the first programs I wrote as a teenager was to track my expenses. It was written in Turbo Pascal and only had room for 10 entries per month. Then I found GnuCash and even later ledger-cli. Unfortunately, I lost about 10 years of my GnuCash files when moving data from one notebook to another. I searched old backups but the data is gone. It would be interesting to run some queries over the data.