01 - EDA Fundamentals: Domain Events, Commands and Message Bus
Event-Driven Architecture Fundamentals: Domain Events, Commands and Message Bus. Imagine an e-commerce system: when a customer completes an order…
Event-Driven Architecture
Series “Event-Driven Architecture”: it starts with “01 - EDA Fundamentals: Domain Events, Commands and Message Bus”. Event-Driven Architecture Fundamentals: Domain Events, Commands and Message Bus. Imagine an e-commerce system: when a customer completes an order, many things must happen asynchronously. Learn domain events, commands…
This series collects 11 articles (approximately 169 minutes of total reading time), designed for a level Intermediate. The main topics covered are Event Sourcing, CQRS, Projection, Eventual Consistency.
11Articles169 minTotal reading timeIntermediateLevel
Event SourcingCQRSProjectionEventual ConsistencyEvent-Driven ArchitectureDomain Events
Series Articles
- 1
- 2
02 - Event Sourcing: State as an Immutable Sequence of Events
Consider how a bank works: your account balance is not just a number in a database—it is the result of every transaction in history.
- 3
03 - CQRS: Separate Read and Write for Independent Scaling
A classic REST API uses the same model to read and write data. CQRS separates the two so each side can scale independently.
- 4
04 - Event Sourcing + CQRS Together: Projection, Snapshot and Consistency
Event Sourcing alone handles the write side in an immutable and auditable way. CQRS alone optimizes reading and writing separately.
- 5
05 - Saga Pattern: Distributed Transactions with Choreography and Orchestration
In microservices there is no such thing as BEGIN TRANSACTION ... COMMIT that crosses service boundaries.
- 6
06 - AWS EventBridge: Serverless Event Bus and Content-Based Routing
Amazon EventBridge is AWS' serverless event bus: it routes events based on content towards Lambda, SQS, Step Functions, API destinations and dozens of other…
- 7
07 - SQS vs SNS vs EventBridge: When to Use Which AWS Service
Three AWS services, three different philosophies. SQS is queue-based, SNS is topic-based pub/sub, and EventBridge is event-driven routing.
- 8
08 - Dead Letter Queue and Resilience in Asynchronous Systems
Dead Letter Queue e Resilienza nei Sistemi Asincroni In qualsiasi sistema asincrono, i messaggi falliscono. In any asynchronous system, messages fail.
- 9
09 - Idempotency in Consumers: Deduplication and Idempotency Key
You set up your event-driven system with SQS, Kafka or EventBridge. Now handle duplicate messages with deduplication and idempotency keys.
- 10
10 - Outbox Pattern: Atomic Publishing of Events with CDC
You have a service that must do two things atomically: save state to the database and publish an event. The outbox pattern solves the dual-write problem…
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11 - Eventual Consistency: Strategies, Trade-Offs and UX Patterns
A user updates their profile, clicks Save and still sees the old name. Eventual consistency strategies, trade-offs and UX patterns.