A workshop by Kevin Ruth
Where I sharpen my product thinking.
I've built products for 15 years: mechanical engineer, then first PM at a startup, now employee #2 at a seed-stage govtech company. Here I write essays when I'm working out an opinion and build small tools when I want to hold myself to one.
Start here
Three ways in.
- A product decision
Stay Close Enough to Stop
The weekly metric I ran a product team on, and how it kept us close enough to customers to see we should stop building the product.
- How I build with AI
Running the Factory
The system of AI agents that builds and reviews Intervals, starting with the fake credential I planted to prove the review gate would catch it.
- A tool you can use
The free forecast
Enter how much work is left and how fast your team finishes it, and it runs 10,000 simulations in your browser to show how likely each finish date is.
01 / The Workshop
Small tools with strong opinions.
Each tool takes one position on how product work should go and makes it checkable. I run them on my own work first, which is how I find out whether the opinion survives.
Stop lying about deadlines.
Give it your scope and your team's real pace, and it runs 10,000 simulations to answer "when will this be done?" with honest odds, then keeps a record of whether the forecast held.
Your language drifted and nobody decided that.
Keeps the agreed wording of your strategy in one file. An agent flags when a draft drifts from it, and every change in wording becomes a dated decision. The template is public; my own copy runs privately.
02 / Temper Line
Essays, where the opinions get worked out.
Temper Line is the essay series. The name comes from blades: the temper line is where hard steel meets soft steel, a boundary you design on purpose. The essays are about the same boundary in organizations, between what they know and what they think they know.
“I walked into the manufacturing plant in Tijuana to see someone erasing the ‘This facility has gone ____ days without an accident’ board and writing in a zero.”
— RESET TO ZERO
Great PMs Don't Agonize
What separates the builders who thrive from the ones who burn out: they've stopped trying to close the gap between documented and real, and learned to work inside it.
Reset to Zero
A press operator in Tijuana lost part of a finger, and every decision that led there was rational from where it was made. What it costs an organization to perform certainty it doesn't have.
Stay Close Enough to Stop
The smallest thing I've ever seen reliably work: measure how often the team is in a room with a real user, and let that number tell you whether to build or stop.
03 / About
Fifteen years building products.
I'm employee #2 at a seed-stage govtech company, where everything is ambiguous all the time. Cold Work is where I think out loud about the gap between what organizations know and what they think they know.
The name comes from metalworking: cold working is shaping metal without external heat, and the material's own resistance to change is what makes it stronger. Most of the product work I'm proud of went the same way, steady pressure on an ambiguous thing until it held a shape. Cold working has a limit, though. Keep hitting the same spot and the metal goes brittle and splits, and I've done that to a roadmap more than once.
If you have an interesting product problem, say hi: hello@coldwork.co.
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