Skip to content

Test with a verdict

Harden or rewrite? A 5-minute prototype test

Whether to harden or rewrite a prototype comes down to 12 questions in four areas: data and access, deployment, tests and code. Tick what is true, also where you do not know, and you get a verdict: harden, harden but fix the weakest area first, or rewrite the core. Rewriting from scratch pays off less often than it seems.

What you fill in and tick stays in this browser window only. Nothing is sent unless you ask for your result by email. It is gone when you close the page, so print your result.

For vibe coders and founders whose app was built in an AI tool or by a freelancer and now has to grow. Tick what is true about your app. Where you don't know, tick it too: with a prototype, "I don't know" is a finding in itself.

Since 2023 we have shipped 15+ production projects and taken over other people's code more than once. Rewriting from scratch pays off less often than people think.

1. Data and access

2. Deployment

3. Tests

4. Code

5. What the result means

TickedVerdictWhat next
0 to 3Almost thereHarden. The code stays. Add tests for the main flows, move keys and permissions to the server, set up backups and monitoring.
4 to 7Halfway thereHarden, but fix the weakest area first. Keep what works and rebuild only the area with the most ticks, usually the data model or login.
8 to 12Getting startedRewrite the core. Rebuild the core on mainstream technology and move the data over. The prototype stays as the spec of what works and what doesn't.

If the third item under data or the last item under code is true, deal with it first, whatever the score: until you get off the platform, every fix happens in someone else's system.

Want certainty on data and access? Run the prototype check prompt. The full pre-launch list is in the 25-point checklist.

More tools for you

Can your users see other people's data? Check your prototype yourself

A prompt for Claude Code or Cursor that goes through your repository in six areas and sorts the findings by severity.

Prototype to production checklist: 25 checks before launch

Login, data, deployment and ownership: what to check before real users get in.

Frequently asked questions

When does it pay to rewrite an app from scratch?
When the data model does not fit the business, nobody can explain the main flow and the code cannot be tested without a rewrite. If eight or more of the twelve items are true, rewrite the core. The prototype then serves as the spec of what works and what doesn't.
What does hardening a prototype mean?
Keeping the code and adding what it needs to run in production: tests for the main flows, permissions and keys on the server, backups and monitoring. It is faster and cheaper than a rewrite.
Why tick what I don't know?
Because with a prototype, "I don't know" is a finding in itself. If nobody knows where the backups are or who has access to the hosting, that is as much a risk as a missing backup.
What if the app sits on a platform I can't get off?
Deal with it first, whatever the score. Until you can export the code and data, every fix happens in someone else's system and you will never fully own it.

Prototype audit

A senior goes through the code and writes down what to harden, what to rewrite and in what order. We get back to you within two business days with a few questions about your work. Then we agree on what we do first.

Tell us what has to ship firstOr a 15-minute intro call