AWS Architecture Learning Hub

Scenario 1: Highly Available Web Application

Problem:
A company wants to deploy a public-facing web application with high availability and the ability to handle unpredictable traffic spikes.

Requirements

• High availability
• Auto scaling
• Secure architecture
• Cost optimization

Proposed Architecture

• VPC across 2+ Availability Zones
• Application Load Balancer
• EC2 Auto Scaling Group
• RDS Multi-AZ
• S3 for static assets
• CloudFront for content delivery

Security Considerations

• Private subnets for application & database tiers
• Security Groups restricting inbound access
• HTTPS via ACM
• WAF for application protection

Trade-offs

• Multi-AZ increases cost but improves availability
• Auto Scaling reduces idle capacity waste
• CloudFront reduces origin load and latency

Scenario 2: Multi-Region Disaster Recovery

Problem:
A fintech application requires disaster recovery with RTO of 15 minutes and RPO near zero.

Solution Design

• Primary region active deployment
• Secondary region warm standby
• RDS cross-region read replica
• S3 cross-region replication
• Route 53 health checks with failover routing

RTO/RPO Strategy

• RPO minimized using database replication
• RTO achieved through automated failover

Cost Considerations

• Warm standby cheaper than active-active
• Data transfer cost between regions

Scenario 3: Cost Optimization Challenge

Problem:
An organization’s AWS bill has increased 35% in the last 6 months. You are asked to optimize costs without impacting performance.

Analysis Approach

• Review Cost Explorer data
• Identify underutilized EC2 instances
• Check unattached EBS volumes
• Evaluate Savings Plans coverage

Optimization Strategy

• Right-size instances
• Purchase Compute Savings Plans
• Implement S3 lifecycle policies
• Enable anomaly detection alerts

Outcome

• 20–30% cost reduction achievable
• Improved cost visibility & accountability