Terraform is an open-source infrastructure as code (IaC) tool created by HashiCorp in 2014. It was developed by Mitchell Hashimoto to help automate and manage cloud infrastructure across providers like AWS, Azure, and Google Cloud. With Terraform, teams can define, deploy, and scale resources in a repeatable and reliable way. It is widely used in DevOps, cloud engineering, and SRE roles. If you are applying for any of these jobs, expect Terraform questions to come up. This guide covers the top 25+ Terraform interview questions and answers to help you prepare.
Fun Fact: Terraform has over 45,900 stars on GitHub, making it one of the most popular infrastructure as code tools.
Basic Terraform Interview Questions
Here are some common Terraform basic interview questions that are often asked at the beginning of interviews to test your fundamentals.
- What is Terraform and what problem does it solve?
Terraform is an open-source Infrastructure as Code (IaC) tool by HashiCorp. It lets you define cloud infrastructure using simple configuration files. Instead of clicking through cloud consoles, you write code. This makes infrastructure repeatable, consistent, and easier to manage across teams.
- How does Terraform differ from tools like Ansible or CloudFormation?
Terraform is declarative and focuses on provisioning infrastructure. Ansible is procedural and better for configuration management. CloudFormation is AWS-specific, while Terraform works across providers like AWS, Azure, and GCP. Terraform also tracks infrastructure state, which Ansible doesn’t.
- What are Terraform providers and why are they used?
Providers are plugins that let Terraform interact with APIs. Each provider maps to a platform like AWS, Azure, or Kubernetes. They define available resource types. Without providers, Terraform wouldn’t know how to manage any infrastructure.
- What is a Terraform state file and how is it used?
The state file stores the current state of your infrastructure. It helps Terraform compare desired vs. actual resources. It tracks metadata and allows Terraform to detect changes. State files can be local or stored remotely for team use.
- What does the terraform init command do?
Terraform init sets up your working directory. It downloads provider plugins and configures the backend. It must be run first before planning or applying.
- Can you explain the structure of a basic Terraform configuration?
A basic Terraform config uses .tf files. Common blocks include:
- provider (e.g., AWS)
- resource (e.g., aws_instance)
- variable (optional inputs)
- output (to display values)
Each block declares something Terraform needs to build or track.
Note: Interview questions on Terraform are divided into basic, intermediate, and advanced levels to assess your understanding at different stages.
Also Read - Top 25+ Ansible Interview Questions and Answers
Terraform Interview Questions for Freshers
These Terraform interview questions and answers are often asked to freshers and entry-level professionals applying for roles in cloud or DevOps.
- How do you install and verify Terraform on your machine?
Download Terraform from the official website. Choose the right version for your OS. Unzip the file and move the binary to a folder in your system’s PATH. To verify, run terraform version in the terminal. It should show the installed version.
- What is Infrastructure as Code (IaC) and how does Terraform fit into it?
Infrastructure as Code means writing code to manage infrastructure. It replaces manual setup with automation. Terraform fits into this by using configuration files to define cloud resources. It makes setup repeatable and helps teams manage changes easily.
- What is HCL and why is it used in Terraform?
HCL stands for HashiCorp Configuration Language. It is a human-readable language used in Terraform files. HCL is simple, clean, and designed specifically for defining infrastructure. It allows you to declare what you want, not how to build it.
- What is the difference between terraform plan and terraform apply?
Terraform plan shows what Terraform will do. It checks the current and desired states and shows changes. No resources are created or modified yet. Terraform apply actually runs the plan and makes the changes to the infrastructure.
- How do you destroy infrastructure with Terraform?
Use the terraform destroy command. It removes all resources defined in your code. You’ll be asked to confirm before deletion. It is often used to clean up test environments or remove outdated infrastructure. Always double-check before using it.
Terraform Interview Questions for Experienced Professionals
Let’s go through some Terraform interview questions and answers for experienced professionals.
- How do you manage Terraform state in a team environment?
Use a remote backend like AWS S3 with state locking via DynamoDB. This keeps the state file shared, secure, and avoids conflicts. Terraform Cloud is another option that offers versioning and access control.
- How do you implement a blue-green or rolling deployment strategy using Terraform?
You can use modules and resource lifecycle rules. For rolling updates, set create_before_destroy = true and use health checks. For blue-green, create two environments and shift traffic using load balancers.
- What are Terraform workspaces and when would you use them?
Workspaces allow multiple state files within one configuration. They are useful for managing dev, staging, and prod without duplicating code. Each workspace keeps its own state but shares the same resources structure.
- How do you handle drift in Terraform-managed infrastructure?
Run terraform plan to detect drift. If changes were made outside Terraform, decide whether to update code or revert infrastructure. Drift should be corrected to avoid unexpected behavior in future applies.
- When would you use depends_on explicitly in Terraform?
Use depends_on when Terraform doesn’t detect an implicit dependency. For example, when a resource indirectly relies on another that isn’t referenced in its arguments. It forces Terraform to create resources in the right order.
Terraform Interview Questions for 3 Years Experienced
- What are the benefits of using modules in Terraform?
- Tell us about a time you used Terraform to solve a deployment problem.
- How do you respond when Terraform throws unexpected changes during plan?
- Describe a challenge you faced with Terraform in a CI/CD pipeline and how you handled it.
- How do you handle secrets securely in Terraform without hardcoding them?
Terraform Interview Questions for 5 Years Experienced
- How have you scaled Terraform usage across multiple environments and teams?
- Describe a complex infrastructure you built using Terraform. What made it challenging?
- How do you coordinate Terraform changes in a multi-developer environment?
- Tell me about a Terraform failure in production. How did you resolve it?
- What is your approach to managing remote state with locking and versioning?
Also Read - Top 25+ CI/CD Interview Questions and Answers
Terraform Advanced Interview Questions
This section covers advanced Terraform interview questions and answers commonly asked in senior-level interviews.
- How do you manage multi-cloud deployments with Terraform?
Use multiple provider blocks within the same configuration. Each block should have its own alias. You can then assign resources to specific providers. This allows provisioning across AWS, Azure, GCP, or on-prem from one codebase.
- How do you lock module or provider versions to avoid breaking changes?
For providers, use version constraints in the required_providers block. For modules, pin the version using a ?ref= in the source URL or specify it in the Terraform Registry. This keeps your infrastructure stable across runs.
- What are some common pitfalls when using count vs for_each?
Count uses index-based references, which can break if the order changes. for_each uses keys, so it’s safer when working with named resources. Mixing both in one module can make the code hard to read and debug.
- How do you write and use custom Terraform providers?
Use the Terraform Plugin SDK in Go. Define schemas, CRUD operations, and configure API calls. After compiling, install it locally or publish it for others. Custom providers are useful for managing internal systems not supported by default.
- What’s the role of Sentinel policies in Terraform Enterprise?
Sentinel is a policy-as-code tool that lets teams enforce rules. You can restrict actions like resource types, naming, or regions. It supports soft and hard enforcement to control how policies are applied during Terraform runs.
Also Read - Top 100+ AWS Interview Questions and Answers
Terraform Scenario Based Interview Questions
Here are some Terraform scenario based interview questions and answers designed to test your practical problem-solving skills.
- What would you do if someone manually changed a resource managed by Terraform?
Run terraform plan to detect the drift. If the manual change is valid, I update the .tf files to match. If not, I apply the plan to revert it. I also talk to the team to avoid future changes outside Terraform.
- How do you prevent a critical resource from being accidentally destroyed in Terraform?
Use the lifecycle block with prevent_destroy = true. This blocks Terraform from deleting the resource during apply. If deletion is needed, you have to remove that flag manually.
- How would you use Terraform to deploy the same module across multiple AWS accounts?
I would define the module once and call it multiple times with different provider aliases. Each alias would use a different account’s credentials. This helps keep the config DRY and consistent across environments.
- What steps would you take if your Terraform apply fails due to missing dependencies?
I check the resource graph and logs. Often, a missing dependency means a resource was removed or changed manually. I use depends_on if needed or adjust the config so Terraform can recreate or reorder the resources properly.
- How would you recover from a corrupted or lost state file?
If I use remote state with versioning (like S3), I roll back to a previous version. For local state, I try importing existing resources back into state using terraform import. Prevention is key, so I always use remote backends.
Note: Reviewing Terraform interview questions and answers for experienced scenario based can also help you prepare for take-home assignments or live coding rounds.
Terraform Coding Interview Questions
Here are practical Terraform coding interview questions to test your hands-on skills with syntax, modules, and real-world configurations.
- Write a Terraform script to create an EC2 instance with a specific tag and security group.
provider “aws” {
region = “us-east-1”
}
resource “aws_security_group” “example” {
name = “example-sg”
description = “Example security group”
}
resource “aws_instance” “web” {
ami = “ami-0c55b159cbfafe1f0”
instance_type = “t2.micro”
security_groups = [aws_security_group.example.name]
tags = {
Name = “MyInstance”
}
}
- How do you use input variables and output values across multiple modules?
Define input variables in variables.tf of the module. Pass values when calling the module:
module “vpc” {
source = “./modules/vpc”
vpc_cidr = var.vpc_cidr
}
In the root module, you can access outputs like this:
output “vpc_id” {
value = module.vpc.vpc_id
}
- How do you use conditional logic with count inside a module?
resource “aws_instance” “example” {
count = var.create_instance ? 1 : 0
ami = “ami-0c55b159cbfafe1f0”
instance_type = “t2.micro”
}
- Show an example of using for_each to create multiple S3 buckets from a list.
variable “bucket_names” {
type = list(string)
}
resource “aws_s3_bucket” “buckets” {
for_each = toset(var.bucket_names)
bucket = each.value
}
How to Prepare for Terraform Interview?
Here are some practical tips to help you prepare for Terraform interview:
- Learn core Terraform commands like init, plan, apply, and destroy
- Practice writing and using modules for reusable code
- Understand how state files work and how to manage them safely
- Work with variables, outputs, and conditional logic
- Study real deployment cases like multi-environment or multi-cloud setups
- Use Terraform with AWS or Azure in practice projects
- Review official docs and practice common scenario-based questions
Wrapping Up
With these 25+ Terraform interview questions and answers, you will be better prepared to face DevOps and cloud interviews. Keep practicing and stay updated with the latest Terraform features.
Looking for Terraform roles? Check out Hirist, where you can find top IT jobs including Terraform job openings.
FAQs
It usually includes 3 to 4 rounds:
HR Screening – Basic questions about your background
Technical Round – Core Terraform and IaC concepts
Hands-on Task – Write or debug Terraform code
Managerial/HR Round – Communication and team fit evaluation
Terraform questions typically come up during cloud, DevOps, or SRE role interviews – especially when the role involves infrastructure automation or AWS, Azure, or GCP.
Azure-based Terraform questions test your knowledge of working with Azure resources using Terraform. Here are some common questions:
How do you configure Terraform to work with Azure RM provider?
What is Azure Cloud Shell and how does it support Terraform?
How do you use a remote backend with Azure Blob Storage?
What are the steps to provision an Azure VM using Terraform?
How do you use Terraform to manage Azure resource groups?
They can be challenging, but not if you have used Terraform in real projects. Expect questions on advanced topics like state management, modules, CI/CD pipelines, and multi-cloud setups. The key is to know how Terraform works in real situations. Practice hands-on and you will be fine.
AWS-focused Terraform questions usually test provider configuration and real deployment examples. Here are some common questions:
How do you authenticate Terraform with AWS CLI credentials?
What is the Terraform resource block to create an IAM role?
How do you set up an S3 bucket with versioning using Terraform?
How do you manage EC2 user data scripts in Terraform?
How do you handle region-specific settings in multi-region deployments?
The average salary for a Terraform professionals depends on the job role, experience, and location. In India, Terraform developers earn about ₹30.8 lakhs per year on average.
Leading firms like Amazon, Microsoft, Accenture, Infosys, Cognizant, and Google Cloud actively hire professionals with Terraform skills for DevOps and cloud automation roles.
Use modules to reuse code
Store state files remotely with locking
Keep secrets out of .tf files
Use version control for all config
Pin provider and module versions
