Implement AUC-ROC, softmax, and logistic regression

Company: TikTok

Role: Software Engineer

Category: Machine Learning

Difficulty: medium

Interview Round: Onsite

Quick Answer: This question evaluates practical implementation skills for core machine learning components—computing AUC-ROC (including ROC point generation and handling ties or uniform labels), implementing a numerically stable softmax, and training logistic regression with cross-entropy loss and optional L2 regularization.