[_ix]

Not the op, but I have some brief thoughts.

Given a bit of time with Terraform, the need for modules becomes obvious as you identify common resources for the infrastructure you're modeling. I thought writing modules first was the "right way," but starting with modules ended up being a waste.

[scaryclam]

I'll second this. I started out not using modules, but figured I'd migrate things over to using them as and when it would make things tidier. I never migrated things.

Modules are really neat but I don't think they're a sensible starting point if you're not doing a lot of repetition or don't exactly know what you need to build yet.