Lab: One model that keeps working without you
Module 16 · Capstone · About 90 minutes · Needs: Modules 1 to 15 (or nothing: Step 1 rebuilds them)
What you are building
In 2017 Google described TFX, the platform behind its continuously retrained models. Its authors wrote that "model validation must be coupled with data validation in order to detect corrupted training data and thus prevent bad (yet, validated) models from reaching production", and that a new model "failing any of these checks is not pushed to serving" (Baylor et al., "TFX: A TensorFlow-Based Production-Scale Machine Learning Platform", KDD, August 2017, sections 2.2 and 5.3). In its Google Play case study, comparing serving logs with training data found features "always missing from the logs, but always present in training"; removing that skew raised installs on the main landing page by 2% (section 7). Uber's version of the same discipline opened Module 10 lesson 2, and Michelangelo opened Module 9 lesson 1.
The capstone builds Kestrel's version end to end and then answers the roadmap's five questions in docs/five-answers.md, every number from this notebook. No cell calls a hosted model.
Which model runs. The Module 10 lab's replay ended with registry version 4, the 21 September retrain, as champion, while the Module 11 lab monitored model v2, the model that served September. This capstone runs v2 end to end: it served September, it has the model card and ADR-010's scope, and it is "last month's model" in question 5. Retrains are registered as challengers that wait for ADR-007's shadow and ADR-010's island check (Step 7).
Open a new Colab notebook, call it module-16-capstone.ipynb, and run each cell in order.