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Courses / Data and analytics tools

Machine learning

Build and evaluate models with scikit-learn in a working notebook.

Start lesson 1Practice interviewTake the assessmentPractice the first unit of every course. No account needed.
62lessons
364checked exercises
13projects, cases and exams
Prepares you for Data scientist and machine learning interviews

Projects, case studies and mock exams

Case study · BeginnerHealthcare scheduling case

Build and evaluate a reminder-priority model without changing appointment access.

6 steps · 18 min
Project · IntermediateCustomer segmentation project

Build customer groups and an indexed behavioral summary.

8 steps · 40 min
Project · IntermediateMembership churn project

Build a held-out churn evaluation and score new customer records.

8 steps · 40 min
Case study · IntermediateRetail metric choice case

Choose a review model from positive-case coverage and review capacity.

6 steps · 18 min
Project · AdvancedFraud review project

Set a fraud review threshold for Nacre Payments when a missed fraud costs eight times as much as a false alarm.

8 steps · 40 min
Case study · AdvancedLogistics model diagnosis

A delivery model looks accurate on its training data. Work out how it will perform on new deliveries and what to report.

6 steps · 30 min
Project · ExpertDemand forecasting project

Forecast demand with past-only features, a time-ordered holdout and a baseline to beat.

8 steps · 40 min
Case study · ExpertMedia and travel launch review

Review a media and travel model before launch, starting from the outcome evidence that is available.

6 steps · 30 min
Mock exam · ExpertModeling job test A

A timed modeling test on chronological holdouts, lagged features, grouped validation, drift and an expected-cost threshold.

12 questions · 40 min
Mock exam · ExpertModeling job test B

A second timed modeling test on rolling folds, unseen entities, nested evaluation, rate shifts, rollback and subgroup recall.

12 questions · 45 min

Work through the modeling workflow in a real Python notebook. You start with features, targets, training and test splits and baselines. Then you build regression and classification models, reusable preprocessing pipelines and model selection experiments. Later work covers clustering, imbalance, calibrated probabilities, interpretation and chronological evaluation. Original projects ask you to score churn, forecast demand, investigate fraud and describe customer segments. Every task checks your fitted objects and results on a second data fixture. You finish with interview practice and two timed job tests.

Interview practice

Explain what you've learned in a full-screen interview. Speak or type, then review your answers against the rubric for your level.

Interview loops by job

Beginner

FreeNo account or card needed. Every lesson in this unit is yours to practice.

The modeling workflow

Frame a decision, identify predictors and define the outcome.

3 lessons

Evaluation splits

Protect validation and test observations from training information.

3 lessons

Regression and baselines

Compare a fitted model with a baseline using held-out errors.

3 lessons

Classification decisions

Fit a binary classifier and measure the consequences of its errors.

5 lessons

Intermediate

Scaling and regularization

Fit transformations on training rows and control coefficient complexity.

3 lessons

Nonlinear estimators

Compare trees, forest averaging and sequential boosting.

3 lessons

Neighbors and customer segments

Use distances for classification and meaningful customer groupings.

4 lessons

Reusable feature preparation

Handle missing values and new categories inside fitted pipelines.

5 lessons

Advanced

Model selection

Build features and compare candidates with validation folds.

4 lessons

Rare events and ranking

Evaluate imbalanced outcomes and choose operational thresholds.

4 lessons

Density and dimensionality

Inspect density clusters and lower-dimensional projections.

3 lessons

Probabilities and interpretation

Calibrate probabilities and inspect predictive contributions without claiming causation.

5 lessons

Expert

Chronological prediction

Validate forecasts with lagged features and strictly later holdouts.

4 lessons

Dependent observations

Keep groups apart and separate model selection from evaluation.

3 lessons

Model operations

Measure drift and mature outcomes before choosing a response.

3 lessons

Model launch decisions

Combine error costs, subgroup evidence and timed assessment work.

7 lessons

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