- Learn AWS
- Architecture
- Event fan-out
Architecture pattern
AWS Event fan-out architecture
when one thing happens and several unrelated things must follow
The producer announces that something happened and stops caring. Each consumer subscribes to what it needs. Adding a fifth consumer later touches nothing that already exists, which is the whole reason to do it this way.
What it runs through
In the order a request or a record moves through it. Each one links to the page that explains it.
- S3Amazon S3
- EventBridgeAmazon EventBridge
- LambdaAWS Lambda
- DynamoDBAmazon DynamoDB
Signals in a brief that point here
Phrases that, when you meet them in a scenario, mean this shape rather than another. They are the tell, and they are what an exam question is built around.
- “when a file is uploaded”
- “several things need to happen”
- “add new consumers later”
- “decouple”
What it costs you
No single place shows you the whole flow, and debugging becomes tracing rather than reading.
Every shape has one. A design decision with no stated downside is usually a decision nobody has finished making.
Learn the services in it
- AWS S3Object storage for any amount of data: files kept as objects in buckets, designed for eleven nines of durability, and private until you grant access.
- AWS LambdaRuns your code in response to events, with no servers to manage. You pay per request and by the millisecond, and a run lasts 15 minutes at most.
- AWS DynamoDBA serverless key-value and document database with single-digit millisecond responses at any scale, and DAX, its in-memory cache, for microseconds.
Shapes it is easily confused with
These run through some of the same services, which is exactly why a brief that fits one can look like it fits another.
Now build it from a brief
Reading a shape and producing one from a scenario that never names a service are different skills, and the exam asks for the second. The scenarios give you the brief; you draw the architecture and it is scored against what the brief requires.