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 application was healthy. CPU was normal. Memory was stable. The database was performing well. Internal services were responding within their expected latency. And yet one part of the system was getting slower. Payment requests. At first, we looked at…
The payment was successful. The ledger had been updated. The transaction had completed. Everything looked correct from the backend. And yet the customer opened the app and saw the old balance. They refreshed. Still the old balance. They checked again.…
We originally introduced Kafka for a simple reason. We needed asynchronous communication. A service would publish an event. Another service would consume it. The producer didn’t need to wait. The consumer could process the event independently. It looked straightforward. Kafka…
1. The Illusion of a Simple API Call Modern banking experiences are built on a dangerous illusion. A user presses: “Transfer $500” The application sends: The response returns: The user sees success. Architecturally, nothing about this interaction is simple. The…
At first, the API was just an interface. A way for one component to call another. Nothing more. Then the system grew. The monolith became multiple services. Teams became independent. Deployments became more frequent. And suddenly almost every important business…
