A PM at an automotive software company named the cost of AI prototyping at his company in one line: there’s a gaping chasm between the prototype and the actual code.
Else prototypes directly on your actual product so engineering sees a pull request to merge, not a sketch to rebuild. The chasm Harry described isn’t in the project plan. The team buys the AI tool, the PM uses it, the prototype works, the demo lands. Then engineering reads what came out, looks at what they would actually have to merge, and starts over.
The chasm is where the cost of an AI prototype actually lives. Not in the building. In the distance between the thing built and the thing that ships.
The chasm has three failure modes.
The prototype is a different object than the thing engineering would build. Lovable, v0, Bolt, Figma Make – all of them produce something that looks right and works in isolation, in a sandbox, against fake data. Engineering reads the prototype, reads the actual product, and the two do not meet. A PM at HP named the structural cost:
“If we could get to a place where the prototype code is actually usable code, then that would be a huge time saver for engineering. And I think it would also mean that the final product is much more aligned with what we prototyped. Because there’s less rework and less reinterpretation of the design.
The design system gets recreated, badly, every time. A VP of design at a B2B SaaS company in our interview corpus described what the rebuild costs the design team:
“When you prototype, you publish and you fix and you get the things to be just right. And then when you have to take that and hand it over to engineers, they completely re-implement. There’s so much that is lost. Then you go back to the plan, figure out how you broke this. We already put in so much work.
Design tokens are wrong, components do not match, spacing is off. The design team rescues the prototype after engineering ships it, which is a different job than the one design thought they were doing.
The prototype rots if it is shipped without the rest of the codebase ever touching it. The signal is loud right now. A 540-comment thread on r/vibecoding from late April sits under the title vibe coded for 6 months. my codebase is a disaster. Six months is the community-canonical time-to-rot for a prototype that lives outside the codebase. The rescue is the third and most expensive failure mode, because by the time it arrives the team is shipping against the prototype, not building from it.
A PM learns the cost of asking. They stop bringing prototypes to engineering that they know will be rebuilt. They cut their own ambition to fit the chasm. The work that survives is the work that already looked like a ticket – the small request engineering would have done anyway, just with a prototype attached. The prototype as a colour swatch, not as a feature.
The work that does not survive is the work the PM most wanted to do. The flow change. The new section of the product. The thing that needed engineering to look at the actual idea, not the spec for the idea.
That is the cost the chasm hides. It is not measured in engineering hours rebuilt. It is measured in PM ambition that never reached the codebase.
Drew Muller is the Director of PM at Ferry International. His team has shipped features through Else into the live product. Engineering reviewed the PR Else opened and merged it. The code Else produced was the code that shipped, with no changes from engineering before merge.
“With Else, we went from validated prototype to production PR in a fraction of the time it used to take. Engineering didn’t touch it until it was ready to merge. – Drew Muller, Ferry International
The chasm closed because the prototype was on the actual product from the beginning. The artifact engineering reviewed was the artifact Drew built. There was no rebuild step because there was nothing to rebuild from.
The PR Else opens is the same shape of PR every other commit on the repo enters through. Same review, same checks, same merge gate. One handoff, the same one the team already has.
The category is starting to recognise the gap. Factory closed a $150M Series C in April with an explicit pitch around being the on-ramp from prototype to production, aimed at the engineering buyer. That is a different shape of bet than Else. Factory is selling to engineering managers with droplets of agent autonomy. Else is selling to PMs and designers with an actual-product prototype that already enters the repo as a PR. Two ways into the same chasm.
The bet Else makes: the side of the chasm worth standing on is the PM side. The PM is the one carrying the validation work that disappears in the rebuild. Closing the gap from the PM side is what makes the validation survive.