📊
ML & Data Science
8 articles
Your Pipeline Passed. Your Dashboard Is Still Wrong.
A green pipeline only proves the code ran. This practical guide shows how contracts, freshness checks, semantic tests, lineage, and safe promotion catch schema drift before it corrupts a dashboard.
Ibrahim Denis Fofanah·Sep 11, 2026·7 min
Your Train-Test Split Is Leaking the Future
A random split can make a forecasting model look excellent by training on records that occur after its test rows. Here is how to build a time-aware evaluation that rehearses production instead of leaking the future.
Ibrahim Denis Fofanah·Sep 7, 2026·10 min
Reasoning Models Explained: What Test-Time Compute Actually Costs You
Letting a model think longer is a real capability (DeepSeek-R1 lifted AIME accuracy from 15.6% to 71.0%) and a real bill you pay in tokens and latency on every query. When it is worth paying, and when it is not.
Ibrahim Denis Fofanah·Aug 11, 2026·7 min
Serving a Model: Endpoint, Batch, or Embedded?
Three ways to serve a model, endpoint, batch, or embedded, and the one question that decides which. Most people default to the always-on endpoint. It is the priciest and most fragile option, and usually the wrong one.
Ibrahim Denis Fofanah·Aug 8, 2026·7 min
Before You Clean Your Data, Ask This One Question: Is It Actually Dirty?
A lender's income field was 23% empty, and the gap turned out to be the best feature in the dataset. Three mechanisms behind missing data, four diagnostics that tell them apart, and why cleaning is a provenance problem in disguise.
Ibrahim Denis Fofanah·Jul 28, 2026·12 min
The First Question Every Data Scientist Asks: What Does One Row Represent?
A falling average order value triggered a discount review. The arithmetic was right and the table was wrong. Why the grain of a table decides whether every metric built on top of it is true.
Ibrahim Denis Fofanah·Jul 23, 2026·12 min
Data Storytelling Teaches You to Present a Finding. Nobody Teaches You to Find One.
Every guide teaches you to present a finding. None teach you to find one. The four questions that do the work, including the one that broke open Google's Sierra Leone trial.
Ibrahim Denis Fofanah·Jul 17, 2026·7 min
7 Pandas One-Liners That Replace 20 Lines of Data Cleaning
Seven vectorized pandas one-liners that replace dozens of lines of manual cleaning code, with copy-paste examples.
Ibrahim Denis Fofanah·Jul 10, 2026·3 min