Infrastructure as Code: Why You Need It, IaC Tools and Best Practices

Meet Infrastructure as Code

As Andreas and Michael Witting define it in their book Amazon Web Services in Action, Infrastructure as Code is "the process of managing and provisioning computer data centers through machine-readable definition files, rather than physical hardware configuration or interactive configuration tools."

The ability to manage IaC provides a lot of important benefits, including:

• Infrastructure versioning. Every change is tracked, reviewable and reversible like application code.

• Cover it with tests. Unit, integration and compliance tests (e.g., with Terratest and policy-as-code) validate the infrastructure before it reaches production.

• Quickly scale the number of environments. Create and remove development, test and temporary review environments whenever you need them.

• Consistent, repeatable environments. Reduce "it works on my machine" issues by defining infrastructure for development, staging and production from the same templates.

• Automated compliance and security checks. Integrate static analysis and policy checks into CI/CD so misconfigurations are caught early.

• Easier collaboration. Use pull requests, code reviews and branching strategies for infrastructure the same way as for application code.

By implementing IaC, your business can:

• Reduce costs since your business can now utilize its computing resources efficiently.

• Increase speed, as engineers can spend more time on improvements and development instead of on routine tasks.

• Decrease risks by replacing manual operations with automation, reducing the chance of human error.

• Improve reliability and consistency by eliminating configuration drift and ensuring every environment is built from the same source of truth.

• Accelerate time‑to‑market because new environments (PoCs, test, regional rollouts) can be set up in minutes instead of days or weeks.

• Strengthen compliance and auditability since every infrastructure change is versioned, reviewable and traceable in Git, which simplifies audits and regulatory checks.

• Enable scalable experimentation by letting teams safely create and destroy short‑lived environments for testing, performance benchmarking and A/B experiments.

• Enhance collaboration between Dev and Ops by treating infrastructure as code, using the same review, CI/CD and workflow practices as application development.

IAC Tools

Match IaC tools to your needs: vendor-specific for single clouds, third-party for hybrid/multi-cloud.

Vendor tools offer deep integration with major cloud providers like Google Cloud Platform; third-party provisioning tools provide multi-cloud support for AWS services and beyond.

Third-party IaC tools shine for hybrid/multi-cloud, with OpenTofu gaining traction for neutrality and compliance.

EPAM IaC Tools

EPAM delivers end-to-end IaC solutions spanning implementation, governance and optimization across Terraform modernization, Terraservices modular architecture, Azure Landing Zone frameworks and AWS CI/CD pipelines — all unified through GitOps practices, enterprise-grade secrets management and agentic AI capabilities for resilient multi-cloud operations.

Key Solutions:

• DevOps Accelerator for Sitecore: Comprehensive Terraform IaC solution that provisions complete Azure infrastructure stacks optimized for Sitecore XM Cloud, XP and XM deployments. Features zero-downtime CI/CD pipelines across geographic regions, automated one-click rollbacks, secure secrets handling and load balancing to support enterprise-scale content management deployments.​

• EngX Assessment: A strategic service that conducts deep audits of existing IaC maturity across engineering pipelines, delivering actionable GitOps transformation roadmaps complete with Power BI-powered metrics dashboards, benchmarking against industry standards and prioritized recommendations for infrastructure as code optimization.​

• Azure Landing Zone: Production-grade IaC framework providing 100+ reusable Terraform modules covering governance policies, network security (WAF), Cloud Adoption Framework compliance, auto-generated documentation, LLM-enhanced operations and FinOps cost optimization extensions for rapid Azure enterprise foundation deployment.​

• Maestro: Unified management platform serving as a single entry point across AWS, Azure, GCP and private datacenters. Includes a custom Terraform provider for hybrid infrastructure automation, multi-dimensional FinOps controls, continuous security compliance monitoring, ML-driven optimization recommendations and full observability over IaC-provisioned cloud resources.​

Together, these solutions create a complete IaC lifecycle.

Infrastructure as Code Best Practices

Adopt these infrastructure-as-code best practices for secure, scalable 2026 deployments: integrate GitOps-driven CI/CD, store state in a remote backend such as S3, and enable state locking with native backend support or DynamoDB for older Terraform setups, while using modular, reusable code.

Use version control for infrastructure provisioning; implement IaC security in continuous deployment pipelines to manage infrastructure safely.

• Store all IaC in Git repositories with PR-based approval workflows for applies.

• Run terraform fmt and validate in CI/CD hooks to enforce code quality.

• Implement policy-as-code using OPA or Sentinel for security compliance scans.

• Enable workspaces named per environment/region (e.g., prod-us-east-1).

• Manage secrets via external providers like HashiCorp Vault or AWS SSM — never hard-code.

• Apply consistent tagging with default_tags and resource-specific labels for cost allocation.

• Detect drift with terraform plan / CI / platform tooling and remediate intentionally. Use ignore_changes only for rare, documented exceptions. Use prevent_destroy to guard critical resources from accidental deletion.

• Test configurations with Terratest; monitor continuous drift detection via tools like Spacelift.​

Remote state inheritance via terraform_remote_state data sources minimizes duplication while ensuring cross-dependency safety.

About Terraform

Terraform remains the gold standard IaC tool in 2026 — a multi-cloud leader with declarative HCL syntax, battle-tested modules and an ecosystem spanning providers from AWS to Kubernetes. Its stateful approach and remote backends make it ideal for enterprise-scale infrastructure provisioning and management.

Modules

A module is a container for multiple resources that are used together. Every Terraform configuration has at least one module, known as its root module, which consists of the resources defined in the .tf files in the main working directory.

A module can call other modules, and can easily include the child module's resources in the configuration. Modules can also be called multiple times, either within the same configuration or in separate configurations, allowing resource configurations to be packaged and reused.

Below is a code example for creating basic network infrastructure in AWS using Terraform variables for environment-specific values:

module "core" {

source = "github.com/lean-delivery/tf-module-aws-core.git?ref=1.0.0"

project = var.project

environment = var.environment

availability_zones = var.availability_zones

vpc_cidr = var.vpc_cidr

private_subnets = var.private_subnets

public_subnets = var.public_subnets

database_subnets = var.database_subnets

create_database_subnet_group = true

enable_nat_gateway = true

}

Use variables for environment-specific settings such as CIDR blocks, subnet lists, and availability zones. Avoid mixing hardcoded values with variable-driven inputs in the same Terraform module example.

More useful Terraform modules can be found on the Lean Delivery project on GitHub.

Workspaces

Each Terraform configuration has an associated backend that defines how operations are executed and where persistent data, such as the Terraform state, is stored. The persistent data stored in the backend belongs to a workspace. Initially, the backend only has one workspace called "default," and thus, there is only one Terraform state associated with this configuration.

Certain backends support multiple named workspaces, allowing multiple states to be associated with a single configuration. The configuration still has only one backend, but multiple distinct instances of that configuration can be deployed without users having to configure a new backend or change authentication credentials.

Multiple workspaces are currently supported by the following backends:

• AzureRM

• Hashicorp Consul

• Google Cloud Storage (GCS)

• Local File System

• Postgres

• HCP Terraform / Terraform Cloud

• AWS S3

Terraservices

Terraservices breaks components up into logical modules, so we can manage them separately. By using Terraservices, we only need to split infrastructure into component stacks (network, shared services, app) and keep a separate state per environment for each component. Typically, if not done already, users can move to a distributed or a remote state setup.

"Terraform, Power On!"

After almost two years of using Terraform, we have finally identified our best practices, which we will share in the examples below.

Let's use AWS as the cloud provider in our example. First, we should prepare infrastructure for a new service, which includes:

• Several Amazon Elastic Compute Cloud (EC2) instances for backend and frontend

• Some of these instances should be balanced with the Application Load Balancer (ALB)

• Relational Database Service (RDS)

• Virtual Private Cloud (VPC) for anything that contains subnets, routing tables, etc.

As the solution for this example, we would use AWS S3 as storage for Terraform state files.

No One Likes Meaningless Duplication

In our approach, we use data inheritance from one Terraservice to another by using the data source terraform_remote_state. Through this data source, we can receive any data output in Terraservices that has already been applied. As a result, in every new Terraservice, we only need to define a few specific variables.

Divide and Conquer

According to the Terraservices concept, we divide our Terraform code into several groups:

1. Terraform state storage infrastructure

2. Core infra: VPC, Subnets, routing tables, etc.

3. Common resources:

   1. Bastion instance (if needed)

   2. RDS

   3. Network connectivity (if needed)

4. Infrastructure for our new service

The last point could contain several separate Terraservices, depending on your target infrastructure:

• Shared resources

• Service's frontend

• Service's backend

Note: If you want to separate production and non-production environments by placing them in different accounts, move the Terraform backend configuration from .tf files to separate .hcl files. It allows you to choose the required backend on the Terraform initial step:

[user@host ~] $ terraform init -backend-config=/path/to/your/tf_backend_config.hcl

The catalog tree in your repository will look like this:

"By the Power of Workspaces!"

Now that we have a Terraform code for our infrastructure, we need it to manage several environments—including production and development. Terraform workspaces are designed exactly for this. First, let's agree on the naming convention.

The workspace name will contain the environment name and AWS region name, e.g., prod-eu-west-1 and dev-us-east-1.

For production and development environments, we should use different input values – that's why each environment should have a separate *.tfvars file. Let's name them according to the workspace name to avoid confusion: prod-eu-west-1.tfvars and dev-us-east-1.tfvars.

The setup sequence example for 1_core would look like:

[user@host 1_core] $ terraform init -backend-config=../dev.hcl # Initialize backend for dev environment

[user@host 1_core] $ terraform workspace new dev-us-east-1 # Create new workspace for dev environment

[user@host 1_core] $ terraform apply -var-file=tfvars/dev-us-east-1.tfvars # Create dev infrastructure by applying Terraform code

[user@host 1_core] $ terraform init -backend-config=dev-backend.tfvars -reconfigure # Remove backend configuration for dev env

[user@host 1_core] $ terraform init -backend-config=../prod.hcl # Initialize backend for production environment

[user@host 1_core] $ terraform workspace new prod-eu-west-1 # Create new workspace for production environment

[user@host 1_core] $ terraform apply -var-file=tfvars/prod-eu-west-1.tfvars # Create prod infrastructure by applying Terraform code

"Infrastructure, Assemble!"

With these tips, you'll have flexible control over each level of your environments. Competent separation of your infrastructure code will allow you to update any part of the infrastructure safely, with minimal risks and minimal effect on other parts of the service.