spjoshis Cloud Architecture
Design scalable, resilient, cost-effective cloud architectures using AWS, Azure, or GCP and cloud-native patterns.
When to Use This Skill
- Cloud migration planning
- New cloud application design
- Multi-cloud strategy
- Cost optimization
- Scalability requirements
- High availability needs
- Disaster recovery planning
- Cloud-native modernization
Core Concepts
1. AWS Well-Architected Framework
## 6 Pillars
**1. Operational Excellence**
- Infrastructure as Code (Terraform, CloudFormation)
- CI/CD automation
- Monitoring and logging
- Incident response
**2. Security**
- IAM with least privilege
- Encryption (at rest, in transit)
- Network security (Security Groups, NACLs)
- Compliance and auditing
**3. Reliability**
- Multi-AZ deployment
- Auto-scaling
- Backup and recovery
- Fault isolation
**4. Performance Efficiency**
- Right-sizing instances
- Auto-scaling policies
- Caching (CloudFront, ElastiCache)
- Database optimization
**5. Cost Optimization**
- Reserved Instances / Savings Plans
- Spot Instances
- S3 lifecycle policies
- Cost monitoring and alerts
**6. Sustainability**
- Efficient resource utilization
- Managed services
- Serverless adoption
- Region selection
2. Reference Architecture - 3-Tier Web App (AWS)
## AWS 3-Tier Architecture
**Tier 1: Presentation**
- Route 53 (DNS)
- CloudFront (CDN)
- S3 (static hosting)
- WAF (Web Application Firewall)
**Tier 2: Application**
- Application Load Balancer
- Auto Scaling Group (EC2 or ECS)
- Multiple Availability Zones
- Security Groups
**Tier 3: Data**
- RDS Multi-AZ (PostgreSQL)
- ElastiCache (Redis)
- S3 (file storage)
**Supporting Services:**
- VPC (network isolation)
- CloudWatch (monitoring)
- Systems Manager (configuration)
- Secrets Manager (credentials)
- SNS/SQS (messaging)
**Diagram:**
Internet ↓ Route 53 → CloudFront ↓ Application Load Balancer ↓ +---+---+---+ | EC2 | EC2 | EC2 | (Auto Scaling Group) +---+---+---+ ↓ ↓ RDS ElastiCache (Multi-AZ)
3. Cloud Migration Strategies (6 R's)
**1. Rehost ("Lift and Shift"):**
- Move as-is to cloud
- Fast migration
- No code changes
- Example: VM to EC2
**2. Replatform ("Lift, Tinker, and Shift"):**
- Minor optimizations
- Use managed services
- Example: Self-managed DB → RDS
**3. Refactor / Re-architect:**
- Redesign for cloud-native
- Microservices, serverless
- Highest benefit, most effort
**4. Repurchase:**
- Move to SaaS
- Example: Email server → Office 365
**5. Retain:**
- Keep on-premises (for now)
- Not ready for migration
**6. Retire:**
- Decommission unused applications
**Migration Plan:**
Phase 1 (Month 1-2): Low-risk apps (Rehost) Phase 2 (Month 3-4): Databases (Replatform to RDS) Phase 3 (Month 5-8): Core apps (Refactor gradually) Phase 4 (Month 9-12): Legacy apps (Evaluate retain/retire)
4. Multi-Cloud Strategy
## Multi-Cloud Architecture Patterns
**Best-of-Breed:**
- AWS: Compute (ECS/EKS)
- GCP: Data analytics (BigQuery)
- Azure: Enterprise integration (AD)
**Geographic Redundancy:**
- Primary: AWS us-east-1
- DR: Azure West Europe
**Vendor Diversification:**
- Avoid lock-in
- Negotiate better pricing
- Skills distribution
**Challenges:**
- Increased complexity
- Multiple billing systems
- Different tooling
- Network connectivity
- Cost tracking
**Tools:**
- Terraform (multi-cloud IaC)
- Kubernetes (portable orchestration)
- Prometheus (monitoring)
- Vault (secrets management)
Best Practices
- Well-Architected Reviews - Regular assessments
- Infrastructure as Code - Terraform, CloudFormation
- Managed services first - Reduce operational overhead
- Multi-AZ deployment - High availability
- Auto-scaling - Handle traffic variations
- Cost monitoring - Set budgets and alerts
- Security by design - IAM, encryption, network security
- Disaster recovery plan - Backup, failover, testing
Resources
- AWS Well-Architected: https://aws.amazon.com/architecture/well-architected
- Azure Well-Architected: https://docs.microsoft.com/azure/architecture/framework
- GCP Architecture Center: https://cloud.google.com/architecture
- Cloud Architecture Patterns: https://docs.microsoft.com/azure/architecture/patterns