ZhiZhi Gewu

What's Really Going On in Machine Learning? A Simplest Example by Stephen Wolfram

From Neural Networks to Rule Arrays: A Minimal Model of Learning

May 16 • KY John

Interchange Fee and the Universal Acceptance of Cards

Payment is fundamentally a two-sided market. Cardholders want more merchants accepting their cards. Merchants want more cardholders. Increasing the…

May 9 • KY John

April 2026

What 50 years of Singapore property prices tell us about risk

Why "average return" lies, why one quarter in 1993 still distorts a 35-year statistic, and what this means for anyone planning to buy property

Apr 25 • KY John

The Hidden Interest Rate in Your Insurance Bill

A mental shortcut for comparing payment plans.

Apr 19 • KY John

When to Use a Blacklist, and When to Use a Rule

After joining the anti-fraud team, I noticed that blacklists are used far more extensively than they were in credit underwriting.

Apr 4 • KY John

1

March 2026

If You Cannot Create It, You Don't Understand It — Even with AI"

I recently built a tiny autograd engine from scratch — just a hundred lines of Python that can compute gradients through a computation graph.

Mar 29 • KY John

Can AI Agents Win a Modeling Challenge? A Replicable Experiment

To get the most out of AI agents, we need to remove human bottlenecks and increase leverage.

Mar 25 • KY John

How Singapore Savings Bonds Work: A Financial Engineering Perspective

Not investment advice

Mar 15 • KY John

1

Fraud Management and the Pricing of Tail Risk

Why tail risk is often underpriced and common fraud metrics can be misleading

Mar 8 • KY John

2

February 2026

January 2026