JuniorIaC & Automation

Explain the Terraform workflow: init, plan, and apply.

What they are really testing: Whether you know plan is a dry-run diff you review before apply makes changes, which is the core safety mechanism of Terraform. Also init for providers/backend.

A real interview question

Explain the Terraform workflow: init, plan, and apply.

What most people say

drag me

You run terraform apply to create your infrastructure.

Skipping plan is the tell. plan is the safety mechanism, a dry-run diff you review before apply, and ignoring it is how people accidentally destroy resources. init (providers/backend) is also part of the workflow.

The follow-ups they ask next

  • Why is reviewing the plan before apply so important?

    It shows exactly what will change, including destroys/replaces. A config tweak can force-replace a stateful resource (like a DB); the plan is your chance to catch that before it deletes data. Apply without reading plan is how accidents happen.

  • What does terraform init actually do?

    Downloads the provider plugins the config requires and initializes the backend (where state is stored), plus pulls modules. You run it first and whenever providers/modules/backend change.

What the interviewer is listening for

  • Knows plan is a dry-run diff reviewed before apply
  • Knows init sets up providers/backend
  • Watches for unexpected destroys

What sinks the answer

  • Jumps to apply, skips plan
  • No notion of reviewing the diff
  • Unaware of init/backend

If you genuinely do not know

Say this instead of freezing. Reasoning out loud from what you do know beats silence every single time, and a good interviewer is listening for exactly that.

Workflow: [init downloads providers and configures the backend (state)], [plan computes and shows the diff, create/change/destroy, without changing anything, a dry run], [apply executes it after you confirm]. The guardrail is [always read the plan before applying, especially watch for unexpected destroys/replaces], which is your chance to catch a dangerous change.

Keep going with iac & automation

All 336 cloud engineer questions

Knowing the answer is not the same as recalling it under pressure

Sign in to send the questions you fumble to spaced recall, so they come back right before you would forget them, and learn the concepts behind them with hands-on labs.

Start free