One of the most common misunderstandings in Terraform is the idea that resources run in the order they appear in your files.
They do not.
Terraform builds a dependency graph.
And that graph, not your layout, determines what happens and when.
This is why moving blocks around rarely fixes broken plans.
And why hard-coding values can quietly destabilize an otherwise “working” configuration.
In this lesson, I explain how Terraform discovers relationships between infrastructure objects, how those relationships form a Directed Acyclic Graph (DAG), and why execution order is always a consequence of logic, not syntax.
You will also learn why:
- Most dependencies should be implicit, not forced
- Parallel execution is not an optimization feature, but a side effect
- Broken graphs lead to fragile plans that fail unpredictably
If Terraform has ever felt inconsistent or mysterious, this concept is usually the missing piece.
Watch the full lesson below to build the correct mental model and avoid years of accidental misconfiguration.