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Thomas Carman

Software Engineer | Full-Stack Developer | DevOps Enthusiast Building innovative solutions with modern technologies

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20 December 2025 - #cloud #aws #kubernetes #infrastructure

Cloud Infrastructure at Scale - AWS, Kubernetes, and Beyond

by Thomas Carman

Designing Cloud-Native Infrastructure

Moving from traditional infrastructure to cloud-native architectures is a journey full of challenges and learning opportunities. I’ve been deep in the trenches of cloud infrastructure design, and here’s what I’ve learned about building scalable, resilient systems.

The Cloud-Native Mindset

Traditional infrastructure thinking doesn’t always translate well to the cloud. Key mental shifts:

Cattle vs. Pets

  • Servers are disposable and ephemeral
  • Automated recovery instead of manual fixes
  • Infrastructure from code, not clicks
  • Immutable infrastructure patterns

Embracing Failure

  • Design for failure from day one
  • Use multiple availability zones
  • Implement circuit breakers
  • Graceful degradation over complete failure

Infrastructure as Code (IaC)

Terraform: The Universal Language

Why Terraform became my IaC tool of choice:

  • Multi-cloud support (AWS, Azure, GCP)
  • Rich ecosystem of providers
  • State management for tracking resources
  • Plan before apply workflow

Example patterns:

# Modular, reusable infrastructure components
# Environment-specific variable files
# Remote state with S3 + DynamoDB locking
# Workspace separation for environments

Best Practices

  • Version control everything
  • Use modules for reusability
  • Implement naming conventions
  • Document all resources
  • Regular state file backups

Kubernetes: Orchestration at Scale

Why Kubernetes?

  • Container orchestration and scheduling
  • Self-healing capabilities
  • Horizontal scaling
  • Service discovery and load balancing
  • Rolling updates and rollbacks

Architecture Decisions

Managed vs. Self-Hosted

  • Started with EKS (AWS managed Kubernetes)
  • Reduced operational overhead
  • Automatic control plane updates
  • Better security patching

Cluster Organization

Production cluster: Critical workloads
Staging cluster: Pre-production testing
Development cluster: Developer experimentation

Namespace Strategy

  • Per-service namespaces
  • Environment separation
  • Resource quotas and limits
  • Network policies for isolation

Cloud Architecture Patterns

1. Microservices on Kubernetes

Service Mesh with Istio

  • Traffic management and routing
  • Service-to-service authentication
  • Observability and tracing
  • Circuit breaking and retry logic

Benefits realized:

  • Independent scaling per service
  • Language-agnostic architecture
  • Isolated failure domains
  • Faster deployment cycles

2. Serverless Components

When to use Lambda:

  • Event-driven processing
  • Irregular traffic patterns
  • Short-lived operations
  • Cost optimization for low-volume endpoints

Hybrid approach:

  • Core services on Kubernetes
  • Background jobs on Lambda
  • API Gateway + Lambda for edge functions
  • Best of both worlds

3. Data Layer Architecture

Database Strategy

  • RDS PostgreSQL for transactional data
  • DynamoDB for high-throughput key-value
  • ElastiCache Redis for caching and sessions
  • S3 for object storage

Backup & Recovery

  • Automated daily snapshots
  • Point-in-time recovery enabled
  • Cross-region replication for critical data
  • Tested disaster recovery procedures

Networking & Security

VPC Design

Public subnets: Load balancers, NAT gateways
Private subnets: Application servers
Database subnets: Isolated data layer
Multiple AZs for high availability

Security Layers

  1. Network: Security groups, NACLs, WAF
  2. Application: IAM roles, least privilege
  3. Data: Encryption at rest and in transit
  4. Monitoring: CloudWatch, GuardDuty, Security Hub

Key Security Practices

  • No hardcoded credentials
  • Secrets Manager for sensitive data
  • Regular security audits
  • Automated compliance checking
  • Principle of least privilege everywhere

Observability Stack

Metrics, Logs, and Traces

Monitoring:

  • Prometheus for metrics collection
  • Grafana for visualization
  • CloudWatch for AWS-native services
  • Custom dashboards for business metrics

Logging:

  • Fluentd for log aggregation
  • ELK Stack for log analysis
  • Structured JSON logging
  • Centralized log storage

Tracing:

  • Jaeger for distributed tracing
  • Request ID propagation
  • Performance bottleneck identification
  • Error rate tracking per service

Cost Optimization

Strategies that saved 40% on cloud bills:

  1. Right-Sizing Resources

    • Regular review of instance utilization
    • Automated scaling policies
    • Spot instances for non-critical workloads
  2. Storage Optimization

    • S3 lifecycle policies
    • Intelligent-Tiering for variable access patterns
    • EBS volume optimization
  3. Reserved Capacity

    • Reserved instances for predictable workloads
    • Savings plans for flexibility
    • Commitment for 1-3 years
  4. Monitoring & Alerts

    • Cost anomaly detection
    • Budget alerts
    • Per-service cost allocation tags

Disaster Recovery

Multi-Region Strategy

Active-Passive Setup:

  • Primary region: All traffic
  • Secondary region: Hot standby
  • Regular failover testing
  • Automated DNS switching

Recovery Objectives:

  • RTO (Recovery Time Objective): < 15 minutes
  • RPO (Recovery Point Objective): < 5 minutes
  • Automated failover procedures
  • Documented runbooks

Automation & Self-Service

Developer Platform

  • One-command environment creation
  • Self-service database provisioning
  • Automated SSL certificate management
  • Pre-configured monitoring and alerting

GitOps Workflows

  • Infrastructure changes via pull requests
  • Automatic syncing with ArgoCD
  • Audit trail for all changes
  • Easy rollbacks

Performance Engineering

Load Testing

  • Regular load tests with k6
  • Identify bottlenecks before production
  • Capacity planning based on data
  • Automated performance regression tests

CDN Strategy

  • CloudFront for static assets
  • Edge caching for API responses
  • Geographic distribution
  • Reduced latency for global users

Database Optimization

  • Read replicas for scaling reads
  • Connection pooling
  • Query optimization and indexing
  • Caching frequently accessed data

Migration Strategies

Moving Legacy Systems to Cloud

Approach:

  1. Assess: Identify dependencies and requirements
  2. Containerize: Package applications in Docker
  3. Pilot: Start with non-critical services
  4. Iterate: Gradually move more services
  5. Optimize: Refactor for cloud-native patterns

Lessons Learned:

  • Start with stateless services
  • Plan for data migration carefully
  • Maintain rollback capabilities
  • Over-communicate with stakeholders

Real-World Challenges

Challenge 1: Database Migration

  • Zero-downtime migration using read replicas
  • Dual-write period for data consistency
  • Extensive testing and validation
  • Successful cutover with < 1 second downtime

Challenge 2: Cost Explosion

  • Unmonitored resources accumulated
  • Implemented tagging strategy
  • Automated cleanup of unused resources
  • 50% cost reduction in 3 months

Challenge 3: Scaling Bottlenecks

  • Identified with APM tools
  • Database connection pool exhaustion
  • Added connection pooling layer
  • Implemented caching strategy

Future Directions

Exploring:

  • Service Mesh adoption (Istio/Linkerd)
  • eBPF for advanced networking and observability
  • ARM-based instances for cost savings
  • Edge computing for lower latency

Key Takeaways

  1. Start with managed services: Focus on business value, not operations
  2. Automate everything: Manual processes don’t scale
  3. Design for failure: It’s not if, but when
  4. Monitor relentlessly: You can’t fix what you can’t see
  5. Cost is a feature: Build cost awareness into architecture
  6. Security by default: Easier to start secure than retrofit
  7. Document decisions: Your future self will thank you

Metrics of Success

After 6 months of cloud-native transformation:

  • 99.95% uptime across all services
  • 40% cost reduction through optimization
  • 10x faster deployment velocity
  • 80% reduction in manual operations
  • Zero security incidents

Closing Thoughts

Cloud infrastructure is not just about lifting and shifting—it’s about fundamentally rethinking how we build and operate systems. The journey requires continuous learning, experimentation, and adaptation.

The best cloud architecture is one that enables your team to move fast while staying secure and cost-effective. It’s a balance of trade-offs, and the right answer always depends on your specific context.


Working on cloud infrastructure challenges? Let’s connect and share experiences!