AWS Solution Architecture Guide
Serverless, scalable, and cost-effective AWS cloud infrastructure.
When to Use
- Designing AWS architecture for new applications
- Optimizing AWS costs
- Building serverless applications
- Creating infrastructure as code
- Multi-region deployments
Architecture Patterns
1. Serverless Web Application
Best for: SaaS platforms, mobile backends, low-traffic sites
Frontend: S3 + CloudFront
API: API Gateway + Lambda
Database: DynamoDB or Aurora Serverless
Auth: Cognito
CI/CD: Amplify or CodePipelineCost: $50-500/month
2. Event-Driven Microservices
Best for: Complex workflows, async processing
Events: EventBridge
Processing: Lambda or ECS Fargate
Queue: SQS (with DLQ)
State: Step Functions
Storage: DynamoDB, S3Cost: $100-1000/month
3. Modern Three-Tier
Best for: Traditional web apps, e-commerce
Load Balancer: ALB
Compute: ECS Fargate or EC2 Auto Scaling
Database: RDS Aurora
Cache: ElastiCache Redis
CDN: CloudFrontCost: $300-2000/month
Service Selection Guide
Compute
| Service | Use Case |
|---|---|
| Lambda | Event-driven, short tasks (<15 min) |
| Fargate | Containerized apps, long-running |
| EC2 | Custom configs, GPU/FPGA |
| App Runner | Simple container deployment |
Database
| Service | Use Case |
|---|---|
| DynamoDB | Key-value, serverless, <10ms latency |
| Aurora Serverless | Relational, variable workloads |
| RDS | Traditional databases |
| DocumentDB | MongoDB-compatible |
| Neptune | Graph database |
Storage
| Service | Use Case |
|---|---|
| S3 Standard | Frequent access |
| S3 IA | Backups, archives |
| S3 Glacier | Long-term archives |
| EFS | Shared file system |
| EBS | Block storage for EC2 |
Infrastructure as Code
CDK Example
import * as cdk from 'aws-cdk-lib';
import * as lambda from 'aws-cdk-lib/aws-lambda';
import * as apigateway from 'aws-cdk-lib/aws-apigateway';
export class ApiStack extends cdk.Stack {
constructor(scope: cdk.App, id: string) {
super(scope, id);
const handler = new lambda.Function(this, 'Handler', {
runtime: lambda.Runtime.NODEJS_18_X,
code: lambda.Code.fromAsset('lambda'),
handler: 'index.handler',
});
new apigateway.LambdaRestApi(this, 'Api', {
handler,
});
}
}CloudFormation Snippet
Resources:
MyFunction:
Type: AWS::Lambda::Function
Properties:
Runtime: nodejs18.x
Handler: index.handler
Code:
S3Bucket: !Ref CodeBucket
S3Key: function.zip
MemorySize: 256
Timeout: 30Cost Optimization
Quick Wins
- Enable S3 Intelligent-Tiering
- Use Savings Plans for predictable workloads
- Set CloudWatch log retention (7-30 days)
- Use VPC endpoints instead of NAT Gateway
- Right-size Lambda memory
Cost Breakdown Tips
- Enable Cost Explorer
- Set up billing alerts
- Tag all resources for tracking
- Review NAT Gateway traffic
- Check data transfer costs
Security Best Practices
| Practice | Implementation |
|---|---|
| Least Privilege | IAM roles with minimal permissions |
| Encryption | KMS for at-rest, TLS for transit |
| Network Isolation | Private subnets, security groups |
| Secrets | Secrets Manager, not hardcoded |
| API Protection | WAF, rate limiting, API keys |
| Audit Logging | CloudTrail, VPC Flow Logs |
Startup Stages
MVP ($20-100/month)
- Amplify full-stack
- Lambda + API Gateway + DynamoDB
- Cognito for auth
- S3 + CloudFront for frontend
Growth Stage ($500-2000/month)
- Add ElastiCache
- Aurora Serverless for complex queries
- CloudWatch dashboards and alarms
- CI/CD pipeline
- Multi-AZ deployment
Scale-Up ($3000-10000/month)
- Multi-region deployment
- DynamoDB Global Tables
- WAF and Shield
- Advanced monitoring (X-Ray)
- Reserved capacity
Common Pitfalls
- Over-engineering early - Don't build for 10M users with 100
- Public S3 buckets - Block public access
- Overly permissive IAM - Avoid
*permissions - No caching - Add CloudFront early
- NAT Gateway costs - Use VPC endpoints