This is your checklist for building anything that touches money. It pushes you away from f64 (precision loss) toward rust_decimal, shows you how to model immutable transactions with Arc for audit trails, and maps fintech domain rules (double-entry accounting, regulatory compliance) directly to Rust patterns. The trace-down tables connect constraints like "money can't disappear" to specific designs like newtypes and RAII transaction scopes. Most valuable if you're building payment systems, trading platforms, or ledgers where getting the money math wrong isn't just a bug, it's a legal problem. Covers currency types, event sourcing for transactions, and the common mistakes that break audit requirements.
npx skills add https://github.com/zhanghandong/rust-skills --skill domain-fintech