Learn with Phoebe Β· Data Science

ML in Production: The Leader Cut

Getting a model to work is the first half of an ML project. Keeping it worth running is the second, and it is decided by a handful of choices that are usually made by default: what problem to scope and what baseline to beat, how the model goes out to real traffic, when it gets retrained and on what, what gets watched and what happens when an alert fires, and when the right answer is to switch it off. Six sessions on those decisions, not the tooling. Each one carries a practitioner card for the team that will build what the leader signs. At the centre is a bench that replays two and a half years of a real electricity market in your browser under eight retrain policies, and prints what each one bought and what it cost.

6sessions
15,104real market rows replayed
8retrain policies on the bench
28readiness tests scored
45min per session

The six sessions 🚒 · from the launch plan to the decision to stop

The running data is Elec2, 45,312 half-hours of the New South Wales electricity market from 1996 to 1998 and the most used concept-drift benchmark there is. The frameworks are Andrew Ng's Machine Learning in Production, the Hidden Technical Debt paper, the ML Test Score and Google's Rules of Machine Learning, each read at source.

πŸ”„ Session 1 Β· advanced

The first deployment is the middle

The lifecycle as a loop with the launch in the middle, the small box of ML code inside a production system and the debts around it, and a readiness score that takes the minimum. Build a one-page readiness sheet.

β–Ά Start here
πŸ“ Session 2 Β· advanced

Scope it like a project

Diligence on feasibility and on value before any data is touched, the baseline a model has to beat, metrics first, and the first rule of machine learning: do not be afraid to launch without it.

the scoping memo
🐀 Session 3 · advanced

Shadow, canary, or all at once

Degrees of automation from human only to full automation, choosing between shadow mode, canary and blue-green, and writing the rollback before the rollout. Why training and serving skew is the test teams skip.

the rollout plan
πŸŽ›οΈ Session 4 Β· bench night

The retrain-policy bench

15,104 real Elec2 rows replayed live under eight policies. Weekly refits buy 4.85 points over never for 130 retrains; an alarm buys 4.08 for 6; retraining before every prediction is worse than no model at all.

β˜… the bench
πŸ“Ÿ Session 5 Β· advanced

Monitor what you will act on

Software, input and output signals, what to watch while labels are late, an action wired to every alert, and the feedback loops that let a model grade its own homework.

the alert-to-action table
πŸ›‘ Session 6 Β· advanced

When not to productionize

What the famous failure rates really say, the kill criteria you write before launch, and the capstone: a one-page production decision memo that can say ship, hold, or stop.

πŸ”’ decision memo
advanced bench night

Your passport 🎫

Clear all three quiz questions in a session and it gets stamped. Six stamps means you can scope an ML project against a baseline, choose how it goes out, set a retrain policy with its price on it, wire monitoring to actions, and write the memo that decides whether it runs at all. Stamps live in this browser only.

What this is not, so you land in the right place 🧭

If your question isGo here instead
How do I track experiments, register models, and write the deploy pipeline and CI?DataOps, builder sessions b5 and b6 β†—
Which drift statistic do I compute, and how do I run evaluation continuously?Model Evaluation, session b9 β†—
Who validates and signs off the model, and what does ongoing monitoring governance require?Model Risk β†—
How do I monitor pipeline freshness, volume and schema before the data reaches the model?Data Observability β†—
My model is wrong in places. What do I fix next?ML Strategy β†—
I have to decide whether, how and for how long a model runs in production, and defend the decision.you are in the right place

The decisions, not the plumbing. Every session ends in a document a leader signs: a readiness sheet, a scoping memo, a rollout plan, a retrain policy with a price, an alert-to-action table, a production decision memo. The tools that carry them out are taught on the neighbouring shelves and linked from each page.

Choose your path πŸ—ΊοΈ

Three doors into the same conviction: shipping a model is a decision you keep making, and every one of those decisions has a price you can put on the page.

πŸ§‘β€πŸ’Ό I approve ML projects 1β†’ 2β†’ 4β†’ 6 readiness, scoping, the price of freshness, the kill decision
πŸ› οΈ I run models in production 1β†’ 3β†’ 4β†’ 5 rollout, retrain policy, monitoring wired to actions
🚒 The whole cut 1β†’ 2β†’ 3β†’ 4β†’ 5β†’ 6 from the launch plan to a signed production decision

What is honest here 🧾

The bench runs on real public rows, recomputed in your browser. Frameworks are quoted from their primary sources. Where a claim comes second-hand, the page says so, and where a famous number has no source, the page says that instead.

ClaimStatus
Every accuracy figure and retrain count on the benchReally computed in your browser from 15,104 rows of Elec2 (Harries 1999, OpenML dataset 151), and matched row for row by an independent Python run
The dollar cost of one retrainSet by you. $500 by default, a placeholder for validation, review, rollout and on-call time; the accuracy numbers never depend on it
Sculley et al. 2015, the ML Test Score 2017, the Rules of Machine LearningRead at source. The "5 percent ML code" line is quoted with its hedge, because the famous figure itself carries no number
Andrew Ng's lifecycle, deployment patterns and degrees of automationCourse pages read; lecture content reported from compiled lecture notes, because the official notes sit behind the course login. The videos and the certificate stay official
Chip Huyen on distribution shift, feedback loops and retrainingRead in the author's own blog posts; the book itself was not opened and none of its numbers are quoted
"87 percent of models never reach production", "85 percent of AI projects fail"Traced and corrected. The first comes from a sponsored panel write-up with no survey behind it; the second is a 2018 forecast about bias, not a failure rate
Worked examples: the readiness scores, the scoping memo, the rollout plan, the alert table, the decision memoConstructed for teaching, and labelled so on each page

The knowledge map 🧠

The whole cut at a glance - hover a session to spotlight its concepts, click any node to jump in.