ZhiZhi Gewu
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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
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KY John
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
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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
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KY John
How Singapore Savings Bonds Work: A Financial Engineering Perspective
Not investment advice
Mar 15
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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
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KY John
2
February 2026
AI in My Daily Workflow: Use Cases and Reflections
The Last Human Job: Deciding What We Want
Feb 20
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KY John
The Risk Metric Translation Layer: Why Precision and FPR Aren't Mirror Images
Sometimes, I found it inefficient to communicate the antifraud team's performance metrics, such as precision and false positive rate, to other teams or…
Feb 7
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KY John
1
January 2026
Absence of Evidence ≠ Evidence of Absence: Rethinking Fraud Prevention KPIs
The Zero-Incident Paradox: Why Silence Isn't Always Golden in Fraud Prevention Using Bayesian reasoning to measure what you cannot directly observe
Jan 24
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KY John
2
Can You Solve This? Calculating KS from a Quarter-Circle ROC Curve
I recently came across an interesting interview question that bridges geometry and risk modeling: “If a model’s ROC curve is a perfect concave down…
Jan 11
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KY John
1
December 2025
Same Math, Different Enemies: The Unit Economics of Credit and Fraud Risk
In my previous post, I discussed standard risk metrics like AUC, KS, Precision, and Recall.
Dec 28, 2025
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KY John
AUC, KS, Precision, and Recall: A Risk Analyst’s Guide
As analysts in the risk management industry, we live and breathe acronyms like AUC (Area Under the Curve) and KS (Kolmogorov-Smirnov).
Dec 20, 2025
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KY John
1
It’s Not the Chaos, It’s the Expectation: A Framework for Deconstructing Anxiety
Recently, I’ve spent time reflecting on the problem of anxiety.
Dec 13, 2025
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KY John
1
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