Let me show you today how I designed messaging abstractions in Emmett, and why I split them into Consumers and Processors. Why I added abstractions like Projector and Reactor, and the trade-offs I chose. I think this can be a good learning experience on how messaging systems are built and the reasoning behind them!

Architecture Weekly's publication is a central hub for architecture enthusiasts, offering insights into architectural design, urban planning, and sustainable architecture practices. Through articles, case studies, and architectural critiques, Architecture Weekly offers insights into iconic buildings, architectural trends, and innovative design solutions. Readers can learn about architectural history, design principles, and environmental sustainability initiatives to gain a deeper understanding of the built environment and its impact on society. Additionally, Architecture Weekly provides updates on the latest architectural projects, design competitions, and industry events to help architects and designers stay informed and inspired.

Architecture Weekly

Explores the architectural design of message processing in Emmett, a TypeScript event sourcing framework. Introduces the separation between Consumers (responsible for fetching messages from sources like PostgreSQL, EventStoreDB, or Kafka) and Processors (handling business logic like projections and reactions). Covers key implementation decisions including processor-owned checkpointing, batching strategies, error handling, backpressure management, and projection rebuilding. Discusses trade-offs between simplicity and flexibility, with practical code examples demonstrating how to configure consumers and processors for different use cases.

Consumers, projectors, reactors and all that messaging jazz in Emmett

Backpressure: When Processors Can’t Keep Up