The text discusses building a payment system using an event-driven architecture, specifically with Confluent, Flink, and MongoDB. It highlights the benefits of event-first thinking, which enables the creation of a generic, data-centric, distributed application runtime that can be used to build various applications. The authors argue that transactions provide guaranteed behavior but are pushed down into database runtime, whereas events offer more control and flexibility. They introduce four pillars for building scalable development: business function, instrumentation plane, control plane, and operations plane. These pillars enable the creation of a system that is simple, scalable, and maintainable. The authors demonstrate how to build a payment system using these pillars, including event streaming, aggregation, and control planes. They also discuss the importance of DevOps and the need for a strong instrumentation, control, and elasticity story.