- Learn AWS
- Architecture
- Serverless API
Architecture pattern
AWS Serverless API architecture
when ordinary requests, and nothing to patch
Request in, response out, with compute that exists only for the length of the call. API Gateway handles the front door and auth; Lambda scales with the request rate; DynamoDB keeps the latency flat as the table grows.
What it runs through
In the order a request or a record moves through it. Each one links to the page that explains it.
- Web clientBrowser / web client
- API Gateway (REST)Amazon API Gateway — REST API
- 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.
- “no operations engineer”
- “unpredictable traffic”
- “pay per request”
- “lookups by key”
What it costs you
Cold starts, a 15-minute ceiling per invocation, and a data model you have to design around the access pattern rather than the entities.
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 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.