The Reproducibility Problem
Why 'it worked on my machine' kills ML projects.
The Reproducibility Problem is a free MLOps Academy lesson on CoddyKit — lesson 4 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the MLOps Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
It Worked On My Machine
The most expensive sentence in ML is it worked on my machine. Reproducibility means anyone can rebuild your exact result, anywhere. 🔁
Many Moving Parts
A training run depends on data, code, library versions, and randomness. Change any one and the result can quietly shift.
Random Seeds
Models initialize and shuffle randomly. Without a fixed seed, two runs on the same data give different weights and scores.
import numpy as np, random
np.random.seed(42)
random.seed(42)Pin Your Versions
A new library version can change defaults overnight. Pinning exact versions keeps your environment stable across machines and time.
# requirements.txt
scikit-learn==1.4.2
numpy==1.26.4Version the Data Too
Code is not enough. If the dataset changes silently, results change with it. You must version data alongside your code.
Track the Config
Hyperparameters hidden in your head are not reproducible. Store them in a config file so every run records exactly how it was set up.
# params.yaml
learning_rate: 0.01
max_depth: 6Log Every Run
An experiment tracker saves params, metrics, and artifacts per run, so months later you can answer how a model was built.
Capture the Git Commit
Record the exact commit hash with each run. That single string ties the result back to the precise code that produced it.
git rev-parse HEAD # store this with the runContainers Lock It Down
A container bundles the OS, libraries, and code into one image. Run it anywhere and the environment is identical every time.
Beware Hidden State
Notebooks run cells out of order, creating results no one can reproduce. Prefer scripts or a clean kernel restart before a final run.
The Payoff
Reproducibility is not bureaucracy, it is trust. It lets you debug, compare fairly, and prove a model is audit-ready.
Quick Check
What does it take to make a training run reproducible?
Recap
Pin data, code, versions, and seeds, log every run, and use containers. Then it works on my machine becomes it works everywhere. ✅
Frequently asked questions
Is the “The Reproducibility Problem” lesson free?
Yes — the full text of “The Reproducibility Problem” is free to read here on the web, and the MLOps Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the MLOps Academy course, upgrade to CoddyKit PRO.
What will I learn in “The Reproducibility Problem”?
Why 'it worked on my machine' kills ML projects. You practise MLOps Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start MLOps Academy?
No prior experience is required. MLOps Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 4 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “The Reproducibility Problem” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this MLOps Academy lesson?
Yes. Every MLOps Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.