Building a Ledger System - Chapter 3: Advanced Topics
This is the third chapter in our five-part series on building production-ready ledger systems. In Chapter 2, we covered transaction state management and async processing. Now we’ll explore advanced topics: multi-currency support, reconciliation systems, and preventing race conditions. Multi-Currency Handling If you’re dealing with multiple currencies, things get interesting: flowchart TD Start([Multi-Currency]) --> Check{Same Currency?} Check -->|Yes| Direct[Direct Transfer] Check -->|No| FX[FX Conversion Required] FX --> Rate[Get Exchange Rate] Rate --> Calc[Calculate Amount] Calc --> Multi[Create 4 Entries] Multi --> E1[Debit Source Account] Multi --> E2[Credit FX Account<br/>Original Currency] Multi --> E3[Debit FX Account<br/>Target Currency] Multi --> E4[Credit Target Account] Direct --> Post[Post Transaction] E1 --> Post E2 --> Post E3 --> Post E4 --> Post Post --> End([Complete]) The key insight: currency conversion is just another account. When converting USD to EUR: ...