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…
The system was becoming increasingly difficult to change. Every time we added a new capability, another service needed to know about it. A payment completed. The ledger needed to update. Notifications needed to be sent. Fraud analytics needed the transaction.…
The monolith had become difficult to work with. Deployments were getting larger. Teams were stepping on each other. Some parts of the system needed to scale independently. A small change in one area could require deploying the entire application. The…
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…
The requirement sounded simple. We needed to add a new column to a production table. The table had more than a billion rows. The business couldn’t afford hours of downtime. And we couldn’t simply stop the application, modify the database,…
