One of the first principles we adopted after decomposing the system was simple: Every service should own its own data. It sounded right. The architecture became cleaner. Teams could deploy independently. Services no longer needed direct access to another service’s…
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 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,…
We had a system that looked healthy. Application CPU was reasonable. Memory was stable. The number of application instances had increased. The load balancer was distributing traffic normally. And yet response times kept getting worse. The first instinct was to…
We had a performance problem. One of the most frequently accessed pieces of data was being read far more often than it changed. The database was handling a large number of repeated reads. The obvious solution was caching. We introduced…
