Member-only story
Saga Pattern and Asynchronous Communication in Banking: Where It Works and Where It Breaks
Explore the architectural boundary between ACID transactions and the Saga pattern in banking. Learn why banks keep a single-writer ledger for money movement while using microservices for orchestration and KYC
3 min readFeb 11, 2026
When people hear that banks use microservices, a common assumption follows almost immediately: everything must have been broken down into small, independent services. Debit here, credit there, reconciliation somewhere else — all loosely connected through events.
In reality, banks are far more deliberate than that.
Banks absolutely use microservices, but they are extremely selective about where they use them. This selectiveness becomes even more important when we talk about asynchronous communication and patterns like Saga.
Where Microservices Actually Fit in Core Banking
Banks do use microservices — but not for splitting real-time money movement.
A pattern you’ll consistently see across large banks is this:
- Microservices handle validation, routing, limits, channels…
