Infrastructure & Operations › Infrastructure as Code

Pulumi and CDK

Infrastructure defined in general-purpose programming languages.

Also known as: Pulumi, CDK, infrastructure in code

Pulumi and CDK are infrastructure-as-code tools that let you define infrastructure in a general-purpose language — TypeScript, Python, Go, C#, Java — instead of a dedicated configuration language. You get real variables, loops, functions, classes and tests, and the tool turns that program into provider API calls.

// illustrative: create a bucket and a server, using normal code
const bucket = new Bucket("reports");
const server = new Server("api", { size: "small" });
server.dependsOn(bucket);

The appeal is abstraction. If your organisation already writes TypeScript or Python, infrastructure can use the same testing, package management and review tools as application code. You can build a reusable “standard service” component once and instantiate it many times, instead of copy-pasting configuration.

The classic mistakes:

• Over-abstraction. Building a framework before you have a second use case. The flexibility to write any code cuts both ways; you can invent complexity no configuration language would allow.
• Forgetting it’s still declarative underneath. The tool tracks expected state and computes a diff, usually via a state file just like Terraform. Abrupt imperative side effects inside your program can surprise the plan.
• Skipping the plan. Because it looks like normal code, people run it like normal code — straight to apply. Read the preview diff first; it’s your safety check.
• Ignoring language-version and dependency concerns. Pin your toolchain as you would for any application, so a build is reproducible.

When to use it: when a team wants to reuse existing language skills and tooling, or when the infrastructure has enough shared patterns that real programming constructs pay off. Declarative configuration languages remain simpler for straightforward resources and are easier for non-programmers to read. They track state and reconcile the same way; the difference is the surface you write in.