More detail
API Gateway handles HTTPS, throttling and authorisation and passes each request to a backend, usually a Lambda function. It’s the classic “serverless API” pattern on the exam.
API Gateway
A managed HTTPS front door that passes requests to your code.
Think of it as: A receptionist who takes every visitor's request and phones the right person.
What to know for Level 0
- API Gateway gives a backend (usually Lambda) a managed HTTPS endpoint, and handles throttling and authorisation before requests reach it. It runs outside your VPC.
- Throttling rejects requests above a rate limit with HTTP 429, so a flood never reaches the backend.
- API Gateway → Lambda → DynamoDB is the classic serverless pattern: nothing to patch or scale, and you pay per request.
- API Gateway is allowed to call a Lambda function by a resource-based policy on the function.