Notebooks are wonderful for exploration. They are a disaster for deployment. This post is about the moment that distinction stopped being theoretical for me, and what I changed in my workflow as a result…

The hidden cost of “it runs in my notebook”

State that lives only in cell outputs. Cell-execution order that nobody else can reproduce. Imports six layers deep that nobody documents…

What replaces them

A small, opinionated stack: a feature pipeline, a training script, a model registry, and a serving layer. Boring. Reliable. Reviewable.