Here are 15 interview questions related to CatBoost, a gradient-boosting framework developed by Yandex, along with their answers:

1. What is CatBoost?

Ans: CatBoost is an open-source gradient-boosting framework developed by Yandex. It is designed to handle categorical features efficiently and provides high-quality predictions in various machine-learning tasks.

2. What are the key features of CatBoost?

Ans: The key features of CatBoost include built-in handling of categorical features, automatic feature scaling, support for both classification and regression tasks, GPU acceleration, and robust handling of missing data.

3. How does CatBoost handle categorical features?

Ans: CatBoost uses an advanced algorithm called ordered boosting, which effectively handles categorical features without requiring manual encoding or one-hot encoding. It automatically converts categorical features into numerical representations.

4. What is the advantage of using CatBoost for datasets with categorical features?

Ans: CatBoost’s handling of categorical features allows it to capture the inherent hierarchical structure in such features, resulting in better predictions compared to traditional gradient boosting frameworks.

5. Can CatBoost handle missing values in the dataset?

Ans: Yes, CatBoost can handle missing values in the dataset. It has an efficient way of dealing with missing data, allowing users to include missing values as a separate category during training.

6. What are the different types of boosting available in CatBoost?

Ans: CatBoost supports two types of boosting: ordered boosting and plain boosting. Ordered boosting is the default and is designed to handle categorical features effectively, while plain boosting is suitable for datasets without categorical features.

7. Does CatBoost support GPU acceleration?

Ans: Yes, CatBoost supports GPU acceleration, which allows for faster training and inference times, especially for large datasets.

8. How does CatBoost handle overfitting?

Ans: CatBoost provides several techniques to handle over fittings, such as early stopping, learning rate schedule, and regularization parameters. These techniques help prevent the model from memorizing the training data and improve generalization.

9. What evaluation metrics are available in CatBoost?

Ans: CatBoost provides a variety of evaluation metrics for classification and regression tasks, including accuracy, log loss, AUC, RMSE, and many others. It also supports custom evaluation metrics.

10. Can CatBoost handle imbalanced datasets?

Ans: Yes, CatBoost includes mechanisms to handle imbalanced datasets. It provides options to balance the class weights and supports evaluation metrics specifically designed for imbalanced classification tasks, such as F1 score and area under the precision-recall curve (AUPRC).

11. How can you handle feature scaling in CatBoost?

Ans: CatBoost automatically handles feature scaling, eliminating the need for explicit feature scaling steps in the data preprocessing phase.

12. Can CatBoost handle large-scale datasets?

Ans: Yes, CatBoost is designed to handle large-scale datasets efficiently. It implements various optimizations to reduce memory consumption and training time.

13. Does CatBoost support cross-validation?

Ans: Yes, CatBoost supports cross-validation. It provides functionality for performing k-fold cross-validation to estimate the model’s performance on unseen data.

14. What is the CatBoost Python API called?

Ans: The CatBoost Python API is called boost. It provides a comprehensive set of classes and methods for building, training, and evaluating CatBoost models.

15. Can CatBoost be integrated with other machine-learning libraries?

Ans: Yes, CatBoost can be integrated with popular machine learning libraries such as scikit-learn. It provides a scikit-learn compatible interface, allowing users to use CatBoost as a drop-in replacement for other gradient-boosting libraries.

16. Can you save and load CatBoost models?

Ans: Yes, CatBoost allows users to save trained models to disk and load them later for inference or further training. The models can be saved in binary format or as a JSON file.