My partner and I have been tracking all our spending for the last five years with hledger (ledger reimplemented in haskell) and some custom import and management scripts inspired by "Full-fledged hledger" [1]. More recently we added Plaid [2] for auto-importing from financial accounts. I love having a plain-text history and being able to ask complex queries.

One unexpectedly-sweet benefit is that your spending is a high-granularity record of where you have been and what you have been doing, encoding some signals you might not have thought to write in a diary. Things like "that was when we were saving for our down payment" or "I was going to coffee shops every day trying to finish my dissertation" or "that was when we had a pandemic." I enjoy looking back through our ledger the same way I enjoy going way back in my gmail history.

[1] https://github.com/adept/full-fledged-hledger [2] https://plaid.com/