- Learn AWS
- Architecture
- Workflow orchestration
Architecture pattern
AWS Workflow orchestration architecture
when many steps, some slow, and failures must unwind
When a process is a sequence with retries, waits and compensations, the state machine should be explicit rather than smeared across services. Step Functions holds the state, retries a step without replaying the ones before it, and gives you one place to see where any order actually is.
What it runs through
In the order a request or a record moves through it. Each one links to the page that explains it.
- API Gateway (REST)Amazon API Gateway — REST API
- Step FunctionsAWS Step Functions
- LambdaAWS Lambda
- RDSAmazon RDS
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.
- “multi-step”
- “if payment fails release the inventory”
- “wait and retry”
- “visibility into every order”
- “long-running”
What it costs you
Another service to model and pay per transition — overkill for a two-step process a queue would handle.
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 API GatewayA managed front door for APIs: REST, HTTP and WebSocket APIs that take each call, check who is calling, throttle it, and pass it to Lambda, another service or any HTTP backend.
- 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 RDS and AuroraManaged relational databases: six engines run for you, plus Aurora, AWS's own MySQL- and PostgreSQL-compatible engine, with standbys, replicas and backups built in.
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.