A hands-on walkthrough. Pick a real situation and follow along.
Before you start
- Choose a real case, not a hypothetical — pressure is where the skill is built.
- Give yourself a clear finish line: *Build a pipeline that cleans messy data.*
The steps
1. Frame it. Write down the situation in one or two plain sentences. No jargon. 2. State the outcome. What does a great result look like? Make it specific enough to check later. 3. Make the move. Do the rep: build a pipeline that cleans messy data. 4. Check against reality. Compare what happened to the outcome you wrote in step 2. 5. Tighten the loop. Note one thing to do better, then run it again.
What good looks like
- Your code is simple to read and hard to break.
- You design for the failure cases, not just the happy path.
- You ship things that hold up in production.
Done when
You can do this without the checklist — and earn the Data Wrangler mark by landing it for real.
Next: see applying it on the job for a realistic scenario and the traps to dodge.