WebsiteNewFor Data scientist or ML engineer

Holdout

Show the delta.

Lets data scientists and ML engineers build a portfolio of experiment cards in their browser and download it as one HTML file to host anywhere.

Download the source

Zip, 279 KB. MIT licence. Built 23 Oct 2026.

Open the app Open full screen

Loading the live site…

This is the real site, not a mock-up. Click around; the button on it opens the working app.

What you get

Everything a website needs, already done.

Pages and screens

Hero experiment card
How it works
Features
Themes
Try the app
Experiment card editor

Features

Experiment cards: dataset, method, metrics, outcome
Tools and languages matrix
Publications and talks section
Chart images stored as data URLs
Three themes with live preview
Edits autosave in the browser
Reorder or hide sections
Export HTML, JSON backup and printable résumé

Palette

#14181f
#555d6b
#636a76
#ffffff
#dedbd2
#0a7d5a

Style

Editorial
Minimal
Warm

Holdout on a phone — On a phone, as shipped.

For developers

A real codebase, not a page builder export.

Stack

Vite, React 19 and TypeScript for the app. The launch page is plain HTML, CSS and a little JavaScript with no build step. Vitest for unit tests, Playwright for browser tests.

Run it

unzip holdout.zip
cd holdout
npm install
npm run dev

In the zip

site/ the launch page with the built app in site/app/
src/ and e2e/ the app source and tests
docs/technical-docs/ architecture, runbook, quick reference
START-HERE.md and LICENSE (MIT)

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Live preview