The Infrastructure as Code Decision
Infrastructure as Code (IaC) is foundational to modern DevOps. The two dominant tools for AWS infrastructure are HashiCorp Terraform and AWS CloudFormation. Both are mature, production-ready, and widely adopted—but they take fundamentally different approaches.
As Terraform consultants and AWS partners who've implemented both tools across hundreds of projects, we'll share the practical differences that matter for your decision.
Quick Comparison
| Aspect | Terraform | CloudFormation |
|---|---|---|
| Provider | HashiCorp (open-source) | AWS (native service) |
| Multi-Cloud | Yes (3000+ providers) | AWS only |
| Language | HCL (HashiCorp Config Language) | YAML / JSON |
| State Management | User-managed (S3, TF Cloud) | AWS-managed |
| Cost | Free CLI / Paid Cloud | Free |
| Plan/Preview | terraform plan (detailed) | Change sets (less detail) |
| Module Ecosystem | Terraform Registry (massive) | AWS Solutions Library |
| AWS Feature Support | Days-weeks after GA | Day 1 support |
| Drift Detection | terraform plan | Drift detection feature |
| Best For | Multi-cloud, complex IaC | AWS-only, simple ops |
When to Choose Each Tool
Compare side-by-side to find the right fit for your organization.
Choose Terraform
Multi-cloud flexibility & ecosystem
Single language across AWS, GCP, Azure. One tool to learn, consistent patterns everywhere.
HCL supports for_each, count, conditionals, and dynamic blocks elegantly.
Thousands of verified modules in Terraform Registry. Battle-tested VPC, EKS, RDS modules.
`terraform plan` shows exactly what will change with detailed diffs before applying.
Manage Kubernetes, Datadog, PagerDuty, GitHub—providers for almost everything.
Industry standard for IaC. Skills transfer across employers and cloud providers.
Choose CloudFormation
AWS-native simplicity & integration
Native integration is seamless. No external dependencies, no state to manage.
Completely free—no subscriptions, no state storage costs, no licensing concerns.
AWS manages state automatically. No corruption, no locking issues, no backend config.
New AWS features supported immediately at launch. No waiting for provider updates.
Single vendor support. AWS handles everything—no finger-pointing between vendors.
View stacks in AWS Console. Designer for visual editing. StackSets for multi-account.
Syntax Comparison
See how the same infrastructure looks in both tools.
Terraform HCL
S3 BucketClean, expressive syntax with explicit dependencies
resource "aws_s3_bucket" "data" {
bucket = "my-data-bucket"
tags = {
Environment = "production"
ManagedBy = "terraform"
}
}
resource "aws_s3_bucket_versioning" "data" {
bucket = aws_s3_bucket.data.id
versioning_configuration {
status = "Enabled"
}
}CloudFormation YAML
S3 BucketYAML-based with intrinsic functions for references
Resources:
DataBucket:
Type: AWS::S3::Bucket
Properties:
BucketName: my-data-bucket
VersioningConfiguration:
Status: Enabled
Tags:
- Key: Environment
Value: production
- Key: ManagedBy
Value: cloudformationState Management Deep Dive
State management is one of the biggest operational differences.
Terraform State
Must configure remote backend (S3 + DynamoDB for locking)
JSON file tracking all managed resources
terraform plan compares state to actual infrastructure
State corruption or loss can be catastrophic
Terraform Cloud handles state automatically
CloudFormation State
State stored in CloudFormation service automatically
Resources grouped in stacks with tracked history
Built-in drift detection feature
No state files to corrupt or lose
Less visibility into what will change
Decision Framework
Answer these questions to guide your decision.
Multi-Cloud Now or Future?
Yes → Terraform. Learn once, use everywhere. No, AWS-only → Either, but CloudFormation removes external dependencies.
Team Experience?
Existing Terraform skills → Terraform. Build on existing expertise. New to IaC → Either; CloudFormation integrates with AWS Console for learning.
Infrastructure Complexity?
Complex logic, many environments → Terraform. HCL handles complexity better. Simple, standard AWS resources → CloudFormation. Don't over-engineer.
Budget Constraints?
Tight budget → CloudFormation. Zero cost. Budget for tooling → Terraform Cloud provides excellent collaboration features worth the investment.
Operational Maturity?
Mature DevOps practices → Terraform. State management is manageable. Early-stage ops → CloudFormation. One less thing to manage.
Common Migration Patterns
Most Common Direction
Organizations often migrate to Terraform as they grow and need multi-cloud or complex IaC patterns. Use `cf2tf` or `former2` tools to convert templates. Import existing resources with `terraform import`.
Simplification
Less common, but valid for AWS-only shops wanting to reduce tooling. Typically done when consolidating on AWS and simplifying operations. Manual conversion required.
Using Both
Some organizations use CloudFormation for core AWS infrastructure and Terraform for multi-cloud resources. Works but adds complexity. We generally recommend standardizing on one.
