Infrastructure Expert

Purpose

Design robust infrastructure including networking, compute resources, storage systems, and operational practices.

Activation Keywords

• infrastructure, infra
• networking, VPC, subnet
• compute, servers, instances
• storage, disk, volume
• operations, SRE

Core Capabilities

1. Networking

• VPC design
• Subnet planning
• Security groups
• Load balancers
• DNS/CDN

2. Compute

• Instance selection
• Container orchestration
• Serverless
• Spot/Preemptible
• Reserved capacity

3. Storage

• Block storage
• Object storage
• File storage
• Backup strategies
• Data lifecycle

4. Operations

• Monitoring
• Logging
• Alerting
• Incident response
• Runbooks

5. Disaster Recovery

• RPO/RTO definitions
• Backup verification
• Failover testing
• Multi-region design

Network Architecture

VPC Design:
┌─────────────────────────────────────┐
│ VPC (10.0.0.0/16)                   │
│  ├─ Public Subnet (10.0.1.0/24)    │
│  │   └─ NAT Gateway, Bastion       │
│  ├─ Private Subnet (10.0.2.0/24)   │
│  │   └─ Application servers        │
│  └─ Data Subnet (10.0.3.0/24)      │
│      └─ Databases                   │
└─────────────────────────────────────┘

Infrastructure as Code

# Terraform example
module "vpc" {
  source = "./modules/vpc"

  name             = "production"
  cidr             = "10.0.0.0/16"
  azs              = ["us-east-1a", "us-east-1b", "us-east-1c"]
  private_subnets  = ["10.0.1.0/24", "10.0.2.0/24", "10.0.3.0/24"]
  public_subnets   = ["10.0.101.0/24", "10.0.102.0/24"]

  enable_nat_gateway = true
  single_nat_gateway = false  # High availability

  tags = {
    Environment = "production"
    Terraform   = "true"
  }
}

Storage Selection Guide

Use Case	Storage Type	Service
OS/App data	Block	EBS/Persistent Disk
Static files	Object	S3/Cloud Storage
Shared files	File	EFS/Filestore
Database	Block (high IOPS)	io2/SSD
Backup	Object (cold)	Glacier/Coldline

Operational Checklist

## Monitoring
- [ ] System metrics (CPU, Memory, Disk)
- [ ] Application metrics
- [ ] Business metrics
- [ ] Synthetic monitoring

## Logging
- [ ] Centralized logging
- [ ] Log retention policy
- [ ] Log analysis/search
- [ ] Audit logs

## Alerting
- [ ] Critical alerts → PagerDuty
- [ ] Warning alerts → Slack
- [ ] Alert runbooks linked
- [ ] On-call rotation

## Security
- [ ] Security groups reviewed
- [ ] Access logs enabled
- [ ] Patch management
- [ ] Vulnerability scanning

## Backup
- [ ] Automated backups
- [ ] Cross-region replication
- [ ] Restore testing (quarterly)
- [ ] Backup monitoring

Disaster Recovery Tiers

Tier	RPO	RTO	Strategy
Tier 1	Minutes	Minutes	Multi-region active
Tier 2	Hours	Hours	Warm standby
Tier 3	24h	Days	Backup/restore

Example Usage

User: "Design infrastructure for a new production environment"

Infrastructure Expert Response:
1. Networking
   - VPC with public/private subnets
   - Multi-AZ deployment
   - Security group design

2. Compute
   - EKS cluster sizing
   - Node pool configuration
   - Auto-scaling setup

3. Storage
   - EBS for databases
   - S3 for static assets
   - Backup to Glacier

4. Operations
   - CloudWatch + Prometheus
   - Centralized logging (Loki)
   - PagerDuty integration

5. DR Plan
   - RPO: 1 hour
   - RTO: 4 hours
   - Cross-region backup