Unintentional infrastructure organization leads to either a fragile monolith or fragmented workspaces with fuzzy dependencies.
Infrastructure tiering is the intentional bucketing of resources into independently deployable layers with explicit contracts via flat inputs and outputs.
A successful model consists of Tier 0 for foundational resources, Tier 1 for the shared platform, and Tier 2 for application-specific resources.
Foundational resources like VPCs belong in Tier 0, shared platforms like EKS clusters in Tier 1, and application-specific resources like S3 buckets in Tier 2.
Tiered designs can be implemented using different tools like Terraform and AWS CDK, passing outputs between tiers using remote state or SSM Parameter Store.
Adopting a tiered approach reduces the blast radius of changes, speeds up deployments, clarifies ownership, and increases tooling flexibility.
Jobs that call for the skills explored in this talk.