How do I approach Machine Learning interview questions?

Machine Learning questions require understanding of core concepts and practice. PracHub provides solutions with explanations to help you master machine learning interviews.

What difficulty level is this interview question?

This is a medium difficulty Machine Learning question, commonly asked during Technical Screen rounds at Apple.

What role is this question designed for?

This question is commonly asked for Data Scientist candidates at Apple during technical interviews.

Construct a Churn-Prediction Pipeline Using Scikit-Learn

Last updated: Mar 29, 2026

Quick Overview

This question evaluates a candidate's ability to design and implement an end-to-end churn prediction pipeline in scikit-learn, testing skills in data splitting and leakage prevention, feature preprocessing for numeric and categorical variables, handling class imbalance, model selection and baselines, hyperparameter tuning, probability calibration, and packaging for production. It is commonly asked to assess practical machine learning engineering and applied model-development competencies—ensuring reproducible validation and proper use of tooling such as Pipeline, ColumnTransformer, GridSearchCV, cross-validation, and joblib—and falls under the Machine Learning category with a primary focus on practical application complemented by conceptual understanding.

Apple

Jul 12, 2025, 6:59 PM

Data Scientist

Technical Screen

Machine Learning

Churn Prediction Pipeline in scikit-learn

Scenario

You are building a churn prediction model for a subscription business. Churn is defined as whether a customer cancels or becomes inactive in the next 30 days. The data is tabular with a mix of numeric and categorical features. The positive class (churners) is typically imbalanced.

Task

Describe, step-by-step, how you would construct, train, validate, and evaluate a churn-prediction model in scikit-learn, including:

Data splitting and leakage prevention
Preprocessing for numeric and categorical features
Model choice and baselines
Hyperparameter tuning with cross-validation
Evaluation and threshold selection
Probability calibration
Packaging the final pipeline for production

Include and explain the use of Pipeline, ColumnTransformer, GridSearchCV, cross-validation, and joblib.

Solution

Show

Comments (0)

Loading comments...

Browse More Questions

More Machine Learning•More Apple•More Data Scientist•Apple Data Scientist•Apple Machine Learning•Data Scientist Machine Learning