For a long time, one region was enough. The application ran there. The database ran there. The message infrastructure ran there. Backups existed. Monitoring was in place. We had redundancy inside the region. From an infrastructure perspective, the system looked…
The transaction used to be simple. At least, it looked simple from the application’s perspective. A customer placed an order. The system processed the payment. The order was created. Inventory was reserved. The ledger was updated. The customer received a…
In a traditional bank, the core ledger is a single-tenant monolith. The database instance belongs entirely to one legal entity. If a query returns a bad row, the blast radius is contained within that bank’s own customers. Banking-as-a-Service (BaaS) destroys…
For 18 months, we built our own fraud detection system. The reasoning seemed sound. Fraud was important. Payments were core to the business. We had strong engineers. We had access to transaction data. And building the capability ourselves would give…
The finding came from an audit. Not from a production breach. Not from an intrusion detection alert. Not from a customer complaint. An auditor was reviewing a payment workflow and asked a simple question: “What prevents one authorized user from…
A single-region deployment is a single point of failure. If an entire data center burns down, the ledger stops. Furthermore, if your users are in Tokyo and your database is in Frankfurt, the speed of light imposes a hard, unbreakable…
