The Whiteboard

I run workshops for a living — fares and ticketing strategy, requirements sign-off, options appraisals. That work lives on shared canvases, which normally means Miro or Figma's FigJam, per-seat pricing, and my clients' thinking sitting on someone else's servers. I wanted the same class of tool inside my own client portal, behind my own access controls, on my own infrastructure.

So I built one. Or more precisely: I described it, argued about it, and reviewed it — while Claude built it. The whole thing went from a blank scoping document to a deployed, multiplayer, client-facing tool over about twenty-four hours of elapsed time, in seventeen planned passes, each one a reviewed pull request with tests.

01What it does

> mid-build test session — two of me, arguing productively

02The honest version of "built in 24 hours"

Let's be precise about the claim, because this is where most vibe-coding stories go soft. I did not build a drawing engine in a day — nobody does. The canvas is Excalidraw, a superb MIT-licensed editor, and standing on it is the whole point. What got built in those twenty-four hours is everything that turns a canvas component into a collaborative service: the realtime sync layer, persistence, authentication and roles, guest sessions, the facilitation kit, comments, presentation mode, the diagram engine integration, exports, and the AI hooks. That's the part you're actually paying Miro for.

And it wasn't one heroic prompt. It was a scoping document first, decisions argued and written down, then passes built branch-by-branch with tests, deployed, and walked through by hand. The walkthroughs mattered: automated tests proved the buttons existed; clicking them found the two that didn't work. Each bug went from screenshot to diagnosed, fixed and redeployed in minutes — that turnaround loop, not the initial generation, is what makes the whole approach viable.

03So — should you cancel your SaaS subscriptions?

Some of them, genuinely, maybe. The economics have shifted for a specific class of tool: the ones where you use a fifth of the features, the per-seat pricing punishes you for inviting guests, and the data would rather live on your infrastructure than theirs. Collaboration tools sit squarely in that class. This whiteboard costs roughly nothing to run, has exactly the features my workshops need and none I don't, and my clients' material stays inside a portal I control end to end.

The caveats are real, though. This is a tool for one consultancy and its clients, not a hardened product for ten thousand strangers — no billing, no SOC 2, no support desk. It leans on a world-class open-source core, which not every category has. And it needs an owner who'll treat it like software: version control, tests, reviewed changes. "Vibe coding" that skips those is how you get something that demos brilliantly and falls over in your first real workshop.

But the shape of the conclusion is hard to argue with: a working, multiplayer, client-ready replacement for a well-known SaaS category, built conversationally in a day, running for pennies. Five years ago that sentence would have been fantasy. Now it's a line item I stopped paying.