This one maps fintech domain constraints directly to Rust design decisions. It's built around the core truth that you can't use f64 for money, ever, and shows you how immutability, precision, and audit trails flow down from regulatory requirements into concrete patterns like rust_decimal newtypes and Arc for transaction records. The trace-down tables connect "need immutable transaction records" to specific ownership choices and crate selections. Most valuable when you're starting a payment system or trading platform and need to see why certain architectural choices aren't optional in finance. The currency type example and common mistakes section will save you from the classic blunders.
npx skills add https://github.com/actionbook/rust-skills --skill domain-fintech