What is Infrastructure as Code (IaC)?
Updated
Infrastructure as Code (IaC) is the practice of defining and provisioning computing infrastructure — servers, networks, databases, cloud resources — through machine-readable configuration files kept in version control, rather than through manual console clicks or ad-hoc scripts. The environment becomes a repeatable artifact you can review, test, and recreate.
The payoff is consistency and auditability. Because the desired state is written down and versioned, the same definition produces the same environment every time, changes go through the same review as application code, and there is a complete history of who changed what and when — the difference between infrastructure you can reason about and infrastructure that only one person understands.
Declarative vs. imperative, and how IaC works
Most modern IaC is declarative: you describe the desired end state — three servers, this network, that database — and the tool figures out the actions needed to reach it, reconciling reality against the definition. This differs from imperative scripting, which specifies the steps rather than the outcome and is harder to reason about when run repeatedly. Declarative definitions are idempotent: applying them twice yields the same result.
In practice, IaC definitions live beside application code in the same repository, so a change to infrastructure is a pull request like any other — reviewed, tested in a pipeline, and applied automatically. Common building blocks include cloud-provisioning tools, configuration-management tools, and managed-platform descriptors; what unifies them is that the source of truth is a file under version control, not the state of a console.
Why IaC underpins modern delivery and modernization scoring
IaC is a prerequisite for the higher tiers of delivery performance. Reproducible environments make it safe to deploy frequently, recover quickly, and stand up identical staging and production. It also closes a common audit gap: with infrastructure defined as reviewed code, change management over the environment is evidenced automatically rather than reconstructed from memory.
This is why platform-modernization assessments treat the presence of genuine IaC as a distinct maturity signal, separate from simply running in the cloud. Deploying to a managed platform is a modern choice; codifying the whole environment so it can be recreated from a repository is a further step. The two are related but not the same, and a good assessment credits them independently rather than inferring one from the other.
Frequently asked questions
What is Infrastructure as Code?
It is the practice of provisioning and managing infrastructure through version-controlled configuration files instead of manual setup. The desired state is written down, reviewed, and applied by tooling, so environments are repeatable, auditable, and recoverable rather than dependent on one person's memory of how the console was configured.
What is the difference between declarative and imperative IaC?
Declarative IaC describes the desired end state and lets the tool determine the steps to reach it, making it idempotent — safe to apply repeatedly. Imperative IaC specifies the sequence of steps instead. Most modern tools are declarative because describing the outcome is easier to review and less error-prone than scripting every action.
Does using a managed cloud platform count as IaC?
Not by itself. Deploying to a managed or serverless platform is a modern architectural choice, but IaC specifically means the environment is defined as version-controlled code that can recreate it. A repo can deploy to the cloud without codifying its infrastructure, which is why maturity assessments score cloud adoption and IaC as separate signals.
Published by ShipReady Metrics, an evidence-based technology and compliance intelligence platform. This guide is educational and vendor-neutral.