Levels.fyi reduced their AWS bill by $2,410 monthly ($28,900 annually) through systematic cost analysis using LLMs to query AWS services. Key savings came from optimizing RDS backup retention policies (reducing 15.7TB to 3TB for $1,200/month savings), relocating WAF and CDN logs to cheaper storage and filtering to only blocked events ($600/month savings), and addressing a growing mystery line item.
AWS now charges for public IPv4 addresses, making IPv6-first Kubernetes deployments financially attractive. isp6 built their order-management platform as IPv6-first EKS on AWS, discovering that while most infrastructure supports IPv6, dependencies like RDS still require IPv4 fallbacks, limiting total cost savings.