Feature Engineering
Often the highest-leverage skill in practical ML: better features beat fancier models.
Learn it
Learn to create informative features (ratios, dates→parts, text→counts), select useful ones, and avoid target leakage. This is where domain knowledge shines.
By the end you’ll be able to
- Create informative features
- Avoid target leakage
Free resources
- Kaggle Learn — Feature Engineering(opens in a new tab)Start here
Create/select features, target encoding
Free5 hr - Kaggle Learn — Intermediate ML (Data Leakage)(opens in a new tab)
Dedicated lesson on avoiding target leakage
Free4 hr - Data Leakage in ML (Wikipedia)(opens in a new tab)
Reference on types of leakage
Free
Practice
Add two new engineered features to a dataset and measure whether they improve your model.
Build it — your output
A before/after experiment showing model performance improve after adding engineered features.
Prove it — check yourself
You’re ready to move on when you can honestly say yes to each:
- Can you create a new feature from existing columns?
- Can you avoid target leakage?
- Can you measure a feature’s impact?
Do it with AI
Use a free AI tool as your tutor and pair-programmer. Copy a prompt below into Claude, ChatGPT, or Gemini (for building, try Cursor or Copilot).
The habit: Try it yourself first — a little struggle is where the learning actually happens. Then ask for a hint before the answer — never copy blindly.
- Understand itClaude / ChatGPT / Gemini
I'm a beginner learning "Feature Engineering". Explain it in simple terms with a real-world analogy, then ask me ONE question to check my understanding — don't reveal the answer.
- PracticeClaude / ChatGPT / Gemini
Give me 3 short practice problems on "Feature Engineering" (my goal: create informative features), from easy to hard. Don't include the solutions yet — I'll try them first, then ask you to check.
- Get unstuckClaude / ChatGPT / Gemini
I'm stuck on this exercise about "Feature Engineering": [paste your attempt here]. Give me ONE small hint to move forward — do NOT give me the full solution.
- Build & reviewCursor / Copilot
Here is my work for a "Feature Engineering" task: [paste your code or answer]. Review it: point out what's wrong and WHY, and suggest improvements — but let me make the fixes myself.
- Prove itClaude / ChatGPT / Gemini
Quiz me on "Feature Engineering". Ask me 5 questions one at a time, wait for my answer each time, then tell me if I'm right and briefly why.