🟪 1-Minute Summary

XGBoost is an optimized implementation of gradient boosting with built-in regularization, parallel processing, and tree pruning. Dominates Kaggle competitions. Key features: handles missing values, L1/L2 regularization, early stopping, feature importance. Faster than sklearn’s GradientBoosting. Hyperparameters similar to GB but with extras (reg_alpha, reg_lambda). Default choice for structured/tabular data competitions.


🟦 Core Notes (Must-Know)

What Makes XGBoost Special?

[Content to be filled in]

Key Features

[Content to be filled in]

  • Regularization (L1/L2)
  • Parallel processing
  • Tree pruning
  • Handles missing values
  • Cross-validation built-in

Key Hyperparameters

[Content to be filled in]

  • n_estimators
  • learning_rate (eta)
  • max_depth
  • reg_alpha (L1)
  • reg_lambda (L2)
  • subsample
  • colsample_bytree

When to Use XGBoost

[Content to be filled in]


🟨 Interview Triggers (What Interviewers Actually Test)

Common Interview Questions

  1. “What’s special about XGBoost vs regular Gradient Boosting?”

    • [Answer: Regularization, faster, pruning, handles missing values]
  2. “Why is XGBoost so popular in competitions?”

    • [Answer: State-of-the-art performance on tabular data]
  3. “What regularization does XGBoost use?”

    • [Answer: L1 (reg_alpha) and L2 (reg_lambda)]

🟥 Common Mistakes (Traps to Avoid)

Mistake 1: Using default hyperparameters

[Content to be filled in - must tune]

Mistake 2: Not using early stopping

[Content to be filled in]

Mistake 3: Forgetting to scale (actually not needed for trees)

[Content to be filled in]


🟩 Mini Example (Quick Application)

Scenario

[Classification with XGBoost and hyperparameter tuning]

Solution

import xgboost as xgb
from sklearn.model_selection import train_test_split

# Example to be filled in


Navigation: