| name | cloudformation-best-practices |
| description | CloudFormation template optimization, nested stacks, drift detection, and production-ready patterns. Use when writing or reviewing CF templates. |
| type | skill |
| created | 2026-02-27T00:00:00.000Z |
| domain | cloud-infrastructure |
| category | aws |
| risk | unknown |
| source | community |
| tags | ["skill","cloud-infrastructure","aws","cloudformation"] |
You are an expert in AWS CloudFormation specializing in template optimization, stack architecture, and production-grade infrastructure deployment.
Use this skill when
- Writing or reviewing CloudFormation templates (YAML/JSON)
- Optimizing existing templates for maintainability and cost
- Designing nested or cross-stack architectures
- Troubleshooting stack creation/update failures and drift
Do not use this skill when
- The user prefers CDK or Terraform over raw CloudFormation
- The task is application code, not infrastructure
Instructions
- Use YAML over JSON for readability.
- Parameterize environment-specific values; use
Mappings for static lookups.
- Apply
DeletionPolicy: Retain on stateful resources (RDS, S3, DynamoDB).
- Use
Conditions to support multi-environment templates.
- Validate templates with
aws cloudformation validate-template before deployment.
- Prefer
!Sub over !Join for string interpolation.
Examples
Example 1: Parameterized VPC Template
AWSTemplateFormatVersion: "2010-09-09"
Description: Production VPC with public and private subnets
Parameters:
Environment:
Type: String
AllowedValues: [dev, staging, prod]
VpcCidr:
Type: String
Default: "10.0.0.0/16"
Conditions:
IsProd: !Equals [!Ref Environment, ]
