In Plain Terms

What it looks like when a team actually uses it

The worked example, told in plain language — for product leaders, designers, and anyone who isn't going to read a file tree. One real-shaped feature, start to finish, and what changes because of it.

There's a detailed, technical tour of the example — folders, standards, the works. It's there to prove the thing is real. If that tour made your eyes glaze, this page is for you instead. You don't need to understand a single file to understand what ProductHarness changes. Here is one feature, the way it actually plays out.

The technical detail is the receipts. The story below is what the receipts are for.

Receipt matching at Meridian

Meridian is a company that makes expense-management software. (It's invented, so we can show real detail without anyone's confidential information.) Here's a problem its product team took on.

01
A problem worth solving

After people upload their receipts, they have to match each one to the right charge on their company card — by hand, one at a time. It's tedious, and it's the exact step where expense reports stall and people give up. Support tickets pile up. As card spending grows, the manual work grows with it.

02
A working version the same afternoon

Instead of writing a long specification and waiting weeks to see anything, the product manager works alongside an AI assistant and builds a working version that day — not a slide, not a mockup, something stakeholders can actually click and try. Because the company's standards are already in the room, what gets built looks and behaves like the real product, not a throwaway.

03
Reactions to something real

Stakeholders respond to real behavior, not a description of it — and the team learns the thing that matters most: a wrong match is worse than no match, because it can send money to the wrong place. So the goal isn't "match as much as possible." It's "only match when we're sure." Trust is the constraint. You learn that by watching people use the thing, not by guessing in a meeting.

04
A decision made on evidence

The team runs the working version against real (anonymized) past data and finds the setting that's accurate enough to trust — matching the large majority of receipts while almost never getting one wrong. The judgment call — how sure is sure enough — gets written down, with the reasoning, so a year from now anyone can see why it was set where it was.

05
Built once, everywhere at once

Engineering builds the real thing from the version that was already validated — not from a document that might be out of date. And the busywork around it — the tickets for the engineers, the checklist for QA, the documentation — is generated from the one place the work already lives. The product manager never re-types the same thing into five different systems. That re-typing is the tax this removes.

06
Measured — and honest about it

After launch, the team checks whether it actually helped, against the original problem. Here's the honest part: the previous feature this team shipped — a faster way to upload receipts in bulk — turned out not to move the needle at all, because uploading was never the real bottleneck. That uncomfortable result is exactly what pointed them at matching. Nothing was swept under the rug; the lesson became the next, better bet.

What actually changed

01
Decisions happen before the expensive part

Stakeholders react to working software before engineering commits real time. The wrong-thing-built-then-discovered cycle gets cut off at the start.

02
The work is written once

One source feeds the backlog, the documentation, and the test plan automatically. No one spends their week translating the same intent into five different tools.

03
Nothing gets lost

Every decision keeps its reasoning, in order, forever. When a choice is questioned three quarters later, the "why" is on the record — not in someone's memory.

04
Bets get measured

The team checks whether each release moved the metric it was meant to, and lets honest results redirect the next decision. It learns instead of guessing.

The team writes the work — once One source of truth requirements · designs decisions · prototypes generated automatically Backlog / tickets Documentation Test cases The flow is one-way: these systems receive from the source — they don't feed back into it.
Product work is authored once, in one place — and the backlog, the documentation, and the test cases are generated from it. Nobody re-types the same thing into five systems.

Want to see the receipts?

Everything above is backed by a real, browsable example — the same feature, with the actual standards, the validation evidence, the decision record, and the generated tickets. It's more technical, and that's the point: it's the proof.

The worked example →

If you'd like to see what this would look like for your own team, that's what a training engagement is for. Engagements →