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It’s a place to share what I learned, and I experienced

Fraud Detection Modeling: Lessons from Practice

Background Fraud detection modeling is often considered a classic binary classification problem. In practice, however, even a classifier with 99% recall or 99% PR-AUC can still be useless. An extremely imbalanced dataset can cause a classifier to produce a huge number of false positives, which will reduce profits from transaction fees. In this article, I will discuss two major topics that are rarely discussed: How to define a proper goal and a measurable metric Data preparation In the next article, I will cover training practices: ...

October 1, 2026

Re-Learn PCA in a Visual Implementation

Background Recently, I have been thinking about how to present an example that is both easy to understand and practical. So I decided to write an article to not only implement PCA but also show how it works. Principle Component Analysis (PCA) Principle Component Analysis (PCA) is a powerful technique for multiple variables analysis. PCA reduces the dimensionality of the data while preserving as much variance as possible. It is usually applied to: ...

August 3, 2024

About This Blog

This is a blog sharing what I learned, and my experience from my work. It’s mainly related to data science, software engineering.

June 20, 2024