Learning machine learning - Random forest and gradient boosting

This classification ML model tries to predict whether a person will default or not while repaying debt. Implemented decision trees, random forest and gradient boosting.This was the dataset. The ROC(AUC) score of this models were:

• Decision tree: 0.785
• Random Forest: 0.8252
• Gradient Boosting: 0.824

All the experiments and learning are embedded below as a gist.