Why transformed probabilities need a Jacobian adjustment
Square a random variable and the probability density stretches with it. Here is why naive substitution integrates to 2.0 instead of 1, and how the Jacobian factor puts it back.
Tag: AI
You can pivot your tech career without starting over
Feeling stale in your role? A tech career pivot usually means reusing what you already know rather than deleting it. Four common moves, plus what three people who made the switch had to say about it.
RFM analysis for WooCommerce customer segmentation
Reporting plugins bloat the database and still guess at who your best customers are. Here is how I build RFM scores from WooCommerce order data in Pandas, and what the segments are actually good for.
Why I use GliNER2 for structured data extraction
A client had ten thousand messy biographical records that needed to become a clean knowledge graph. GPT-4o would have done it and cost a fortune, so I used GliNER2 instead: schema-driven extraction that runs on a CPU.
How I handle covariance shift with IPW
A WooCommerce recommendation engine scored 0.85 AUC in staging and fell apart on launch day because the live audience did not match the training data. Inverse probability weighting is how I got an honest read on what the model was really doing.
Cyclical feature encoding and the midnight paradox
A client’s hourly sales model lost its accuracy every night at midnight because it read 23:00 and 00:00 as far apart. Sine and cosine encoding puts the hours back on a circle, which is where they belong.
Distributed computing with Ray, from one core to 64
A client bought a 64-core Threadripper and their script still ran on one core for an hour. Ray brought it down to about two minutes, with less code than the multiprocessing version I tried first.
Specialized data roles beat the generalist stack
Data work is moving away from generalists and toward people who know the domain, whether that is archaeology, renewable energy or sport. I got this wrong once on a solar reporting engine, and the fix was domain logic rather than a better query.
Agentic AI workflows that survive a failed API call
A client’s research pipeline kept hallucinating specs until we stopped writing one giant prompt. Notes on using IntelliNode’s VibeFlow to compile intent into a task graph, plus the code we run in production.
A WordPress development workflow that survives bad hosting
A WooCommerce site broke because its new host had no bcmath extension. The proposed filter for the required PHP extensions list in core would catch that kind of gap before checkout starts failing.