Concepts

Serverless

Cloud computing model where the provider manages infrastructure automatically, allowing code execution without provisioning or managing servers, paying only for actual usage.

seed#serverless#cloud#faas#event-driven#aws#scaling

What it is

Serverless is a cloud execution model where the provider allocates resources dynamically and charges only for compute consumed. It doesn't mean "no servers" — it means the developer doesn't manage them. The provider handles provisioning, scaling, patching, and availability.

Fundamental characteristics

  • No server management: no instances to configure or maintain
  • Automatic scaling: from zero to thousands of instances based on demand
  • Pay per use: charged per invocation/duration, not idle time
  • Event-driven: functions execute in response to events

Serverless services in AWS

ServiceFunction
LambdaFunctions as a Service (FaaS)
API GatewayHTTP/REST/WebSocket APIs
DynamoDBNoSQL database
S3Object storage
Step FunctionsWorkflow orchestration
EventBridgeEvent bus
SQS / SNSMessaging

Common patterns

  • API backend: API Gateway → Lambda → DynamoDB
  • Event processing: S3 upload → Lambda → processing
  • Workflows: Step Functions orchestrating multiple Lambdas
  • Cron jobs: EventBridge schedule → Lambda

Advantages

  • Fast time to market
  • Zero cost when there's no traffic
  • Scaling without intervention
  • Smaller attack surface (no OS to patch)

Limitations

  • Cold starts: latency on first invocation
  • Maximum duration: Lambda has a 15-minute limit
  • Vendor lock-in: provider-specific APIs
  • Debugging: more complex than monolithic applications
  • State: functions are stateless by design

Why it matters

Serverless eliminates server management and payment for idle capacity. For workloads with variable traffic — APIs, event processing, scheduled tasks — the pay-per-execution model can dramatically reduce costs while scaling automatically.

References

Concepts