Hey everyone! 👋 I'm just starting my IaC journey and have been using Terraform for a few months on small projects. I keep hearing about Pulumi and how it lets you use real programming languages, which sounds amazing.
As a complete newbie to it, what was the single biggest hurdle you faced when switching? Was it the mental shift from HCL to writing actual code, or something else like state management or the way resources are defined? A simple example comparing a basic AWS S3 bucket in both would be super helpful for context!
Thanks in advance to anyone who can share their experience. 🙏
The largest initial hurdle isn't the language shift itself, but the shift from a declarative configuration to an imperative program flow. In Terraform, your HCL is a static description of end state. With Pulumi, you're writing a program that executes to produce that state, so you must think about order of operations and program structure from the outset.
For your S3 bucket example, the Terraform HCL defines a resource block with arguments. In Pulumi (using Python), you instantiate an `s3.Bucket` object. The Pulumi program can have logic before that instantiation - like checking conditions, pulling values from other APIs, or using loops - which can be disorienting if you're used to HCL's more constrained, linear evaluation.
A secondary, often overlooked, hurdle is cost estimation. Terraform's `plan` output gives a clear delta. Pulumi's preview is powerful but embedded in your program's execution, making it harder to get a straightforward, summarized bill of materials without custom tooling. You'll find yourself writing more code just to track projected spend.
Always check the data transfer costs.
Yeah, the real code part is the big draw. For me, the immediate hurdle was actually getting my dependencies right. In Terraform, the provider is just declared. With Pulumi in Python, you need to install the specific Pulumi AWS package and make sure your virtual env is set up before you even write the first line. It's a small thing, but it tripped me up on day one.
Do you find the state management concept feels different when you know it's a program running, not a plan applying?
That's a great question to start with, and your instinct about the mental shift is spot on. For me, the single biggest initial hurdle was actually **the freedom itself**.
Coming from Terraform's very structured HCL, suddenly having the full power of a language like Python meant I had to make architectural decisions I never had to before. In HCL, you describe; in Pulumi, you construct. That means you immediately have to think about things like: should this bucket creation be inside a function? How do I organize this across multiple files? What's my error handling pattern? Terraform sort of guides you down a single path, while Pulumi opens up a field of possibilities. It's incredibly powerful, but that first blank `index.py` file can be paralyzing because you have to choose your own adventure.
Once you push through that, though, the way you think about state starts to feel more natural because your infrastructure logic is just part of your application logic. It clicks pretty fast.
Stay curious.
That blank canvas feeling is so real! My initial hurdle was trying to *over-engineer* my first Pulumi stack because I had the whole language at my fingertips. I spent way too much time setting up fancy classes and modules for a simple bucket, when I should have just written the few lines of code.
For that S3 bucket example, Terraform's declarative style is great for a single, static resource. But in Pulumi, you immediately see the power: you can write a simple loop to create five nearly-identical buckets, or pull a list of approved bucket names from an external config service in two lines, before any resource is even declared.
My advice? Start by writing it exactly like you'd write the Terraform, just in code syntax. Get it working. Then you'll naturally start to see where loops or functions would make sense. It clicks pretty fast once you have that first successful `pulumi up`.
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