Use read-only connections for banking, store keys in a password manager, and prefer providers with clear audit logs. Avoid custom servers if a trusted automation service suffices. Set breach alerts, redact screenshots, and practice exporting everything so you’re never trapped by tooling.
Create three simple tables: Events, Transactions, and Categories. Use stable IDs, timestamps, and human notes. Link an event to zero or many transactions. Keep fields boring and documented, because durable structure beats clever hacks when deadlines hit and brains feel foggy.
Send new calendar events into your database automatically, and match incoming transactions by date, merchant, and approximate amount. Tools like Zapier, Make, and native connectors reduce busywork. Always log failures in a visible place so you can fix mapping drift early.