Infrastructure Design

"There is no cloud. It's just someone else's computer." — Chris Watterston

TL;DR

Designs hosting topologies, CDN configurations, DNS setups, SSL/TLS management, and load balancing strategies for reliable, performant web applications. Use this skill when architecting deployment infrastructure, optimizing content delivery, or designing for high availability. [EXPLICIT]

Procedure

Step 1: Discover

• Identify hosting requirements: compute, storage, bandwidth, geographic distribution
• Gather traffic patterns: peak loads, geographic distribution, request types
• Review current infrastructure: providers, configurations, costs
• Assess compliance requirements: data residency, sovereignty, certifications

Step 2: Analyze

• Choose hosting model: serverless (Firebase Hosting + Cloud Functions), containers (Cloud Run), VMs
• Design CDN strategy: edge locations, cache rules, origin shielding
• Plan DNS architecture: domain structure, TTL values, failover records
• Evaluate SSL/TLS: certificate management, HSTS, certificate transparency
• Design for high availability: multi-region, health checks, automatic failover

Step 3: Execute

• Document infrastructure topology diagram with all components and connections
• Configure CDN with appropriate cache headers and purge mechanisms
• Set up DNS with proper TTL, CNAME/A records, and health check routing
• Implement SSL/TLS with auto-renewal (Let's Encrypt or managed certificates)
• Design load balancing: global HTTP(S) LB with backend health checks
• Create Infrastructure-as-Code templates (Terraform, Pulumi, or Firebase config)

Step 4: Validate

• Verify SSL/TLS configuration scores A+ on SSL Labs
• Confirm CDN is serving content from edge locations nearest to users
• Test failover scenarios: what happens when a region goes down
• Validate DNS propagation and TTL behavior during changes

Quality Criteria

• Infrastructure topology diagram covers all components
• CDN configuration optimizes cache hit ratio for target audience
• SSL/TLS scores A+ on Qualys SSL Labs test
• Infrastructure-as-Code enables reproducible deployments
• Evidence tags applied to all claims

Anti-Patterns

• Manual infrastructure changes without Infrastructure-as-Code
• Single-region deployment for globally distributed users
• Wildcard SSL certificates without proper key rotation

Related Skills

• caching-strategy — CDN caching is part of overall cache architecture
• performance-architecture — infrastructure impacts Core Web Vitals
• security-architecture — infrastructure security controls and hardening

Usage

Example invocations:

• "/infrastructure-design" — Run the full infrastructure design workflow
• "infrastructure design on this project" — Apply to current context

Assumptions & Limits

• Assumes access to project artifacts (code, docs, configs) [EXPLICIT]
• Requires English-language output unless otherwise specified [EXPLICIT]
• Does not replace domain expert judgment for final decisions [EXPLICIT]

Edge Cases

Scenario	Handling
Empty or minimal input	Request clarification before proceeding
Conflicting requirements	Flag conflicts explicitly, propose resolution
Out-of-scope request	Redirect to appropriate skill or escalate