Event-First Thinking for Scaling Your Architecture Horizontally

It has taken the last 25 years to establish events as a core system design principle. Events represent facts—immutable occurrences that reshape our domain model.

Transactional consistency was a standard practice before NoSQL. Yet, with the advent of NoSQL, eventual consistency became prevalent.

Event-first thinking is crucial for building a robust foundation for event streaming platforms. It provides horizontal scaling and a common language with the business.

Several considerations come into play when evaluating event-driven architecture. Events are not isolated; they tend to be part of a flow of information, a stream. A stream is an unbounded sequence of related events tied together by an “eventKey.” It simplifies the architecture and allows for greater flexibility. Several combined outcomes represent cumulative behavior across many actors.