In one hour, one Friday night, I built a finished client-facing calculator and put it online. No database. No developer. Just Claude Cowork and a clear idea of what I wanted to make.
But here’s the thing. I wanted to put together a proper tutorial showing what Cowork can actually do and I figured the best way to do that was to build something real, from scratch, in one shot.
Watch the tutorial
What I built
The example is a side hustle calculator. It’s completely front-end with no database, no server stuff, just a clean dynamic tool that runs entirely in the browser. You can set your hourly rate, monthly expenses, savings goal, annual salary and how many hours a week you can realistically put into a side hustle. It then spits out your projected monthly income, how long it’ll take you to hit your savings target and the bit I think is most useful, a straight comparison between what your side hustle pays per hour versus your day job.
What you can do with this
This is the kind of thing you can build in a single session. It’s not a prototype or a proof of concept. It’s a finished, usable tool that’s already live online. Think lead magnets, onboarding tools, client-facing calculators. Stuff that feels bespoke and valuable because it actually is.
Watch the tutorial
I’ve put the full walkthrough on YouTube above. It covers how to use Cowork, the build process and how to get something like this live. Fair warning: the channel has approximately zero subscribers and the other two videos are me documenting the early stages of building a personal brand, so go in with appropriate expectations.