A comprehensive guide to projections and read models in event-driven architecture. Covers the left-fold pattern for building read models from events, synchronous vs asynchronous projections, projection rebuilds (including blue-green rebuilds for zero downtime), idempotency strategies, handling eventual consistency with business stakeholders, and scaling through data partitioning. Includes C# code examples demonstrating shopping cart projections using both in-memory state updates and direct SQL approaches.
Table of contents
Projections can be synchronous and asynchronousProjections rebuildIdempotencyEventual ConsistencyScaling and data isolationTalk is cheap; show me the code!Summing up6 Impressions