Every AI prototyping tool on the market assumes one thing: you’re starting from scratch.
Lovable gives you a blank prompt and a Supabase backend. Figma Make turns a design file into a React app with a public URL. v0 generates components you paste into your project. The model is greenfield—a new thing, from nothing, fast.
That model is useful. It is not the problem most product teams have.
The problem most product teams have
You have a product. It already ships. It has users, a codebase, a design system, a backend, a CI pipeline, and a team that reviews pull requests before anything goes to production.
When you prototype in a greenfield tool, you create a parallel artifact. It lives in Lovable Cloud, or in a Figma design file, or as pasted component code sitting outside your repo. It looks like your product. It does not run on your product.
Then you hand it to engineering.
Engineering looks at the Lovable URL, looks at the design brief, and starts rebuilding—from scratch—on the real codebase. They re-match the design system. They test against the real backend. They align it with the existing component conventions.
The prototype is not the artifact that ships. A rebuilt version of the prototype is.
What “inside your product” means
Else is built for existing codebases. The prototype runs on the real frontend—same components, same CSS, same design tokens, same routing, same backend. There is no parallel artifact. There is no greenfield.
When the PM is done, Else opens a pull request against the repo. Engineering reviews code. Not a design brief. Not a Lovable URL. Code, already written in the team’s stack, already tested against the real backend, already using the real component library.
The prototype is the PR. The PR is the prototype.
Who this is for
- You have a product already in market
- Engineering owns the repo and the merge gate
- You want prototypes that land as PRs, not design artifacts
- You need the prototype to look like your product because it is built from your product
If you’re starting a new app from a blank prompt, Lovable is the right tool. If you’re adding features to the product that already ships, the existing codebase is the advantage—and Else is built to use it.
The downstream effect
When the prototype is on the real codebase, the entire workflow changes:
- Engineering’s job shrinks: review, test, merge. Not rebuild.
- The PM’s output is durable: the PR exists against the repo the moment the prototype is done. It doesn’t evaporate into PRD-limbo during a sprint reshuffle.
- What shipped in the prototype is what ships to users: no translation layer, no “it looked different in the mockup,” no second round of tickets when the shipped version behaves differently.
That’s the existing codebase advantage.