AWS AppSync
Managed GraphQL APIs
A managed GraphQL service (and Pub/Sub over WebSocket with AppSync Events): one endpoint to query many data sources (DynamoDB, Lambda, RDS, HTTP), with real-time subscriptions and offline support.
- Cost$ Low
- Difficulty●●●●●
- Costs money when idle?No
- Serverless
- In examsDVA · SAA
Think of it asLike a waiter who takes one combined order and fetches dishes from several kitchens.
When to use it
✓ Use it when
Web/mobile apps that need GraphQL, data combined from many sources, or real-time updates.
✗ Avoid it when
Simple REST/HTTP APIs → API Gateway.
Common uses
- GraphQL backend for mobile apps
- Real-time chat or dashboards
- Combine data from DynamoDB and microservices
What does it cost?
- Pricing model: Charged by the number of queries/mutations, real-time messages, and connection minutes.
⚠️ Cost traps
Enabling AppSync caching is billed hourly for the cache instance.
Related services
SAA-C03 study guide
AppSync is covered in these study modules: