How it works
Same system, proven flow by flow.
Five steps, a fixed price agreed before we start, and objective acceptance: the new system does what the old one did, or a defect is opened.
How it works · 4–8 weeks · fixed price · 100 % parity
Step 0
Blueprint
One paid week. Scope and price fixed, exit clause.
Step 1
Rebuild
AI agents build; people direct and review.
Step 2
Parity proof
Real flows recorded on the old system, replayed on the new.
Step 3
Cutover
Old system retired.
Step 4
Care + Improvements
Monthly support, evolution and new features.
Four guarantees: typical 4–8 weeks · fixed price agreed before starting · 100 % parity flow by flow · delay credit if we are late.
The five steps
Step 0
Blueprint
One paid week that fixes scope and price.
If you do not continue, you keep everything it produced. The fee is credited in full to the rebuild when it is signed within 30 days.
Step 1
Rebuild
AI agents build the new system while people direct and review every step.
Target stack: Next.js on Vercel, Postgres, Payload, Clerk, Resend; built with Claude.
Step 2
Parity proof
Real user flows are recorded on the old system and replayed against the new one.
Each flow matches or opens a defect. Acceptance is a parity dashboard: one row per flow, each backed by a CI run.
Step 3
Cutover
The new system goes live with your users and your data. The old system is retired.
Step 4
Care + Improvements
Monthly support, evolution and new features, so the system keeps up with the business.
Clean room
The builder never sees the old system.
- One extractor works with the old system. The builder never does.
- Only two things cross the wall: sanitized specs and the recorded oracle, the flows captured on the old system.
- That separation is what makes parity provable: the new system is checked against recorded behavior, not against someone's reading of old code.
Sees the old system
The wall
Sanitized specs →
Recorded oracle →
Never sees it
Acceptance is a dashboard, not an opinion.
Every real user flow is recorded on the old system and replayed against the new one. Each one matches or opens a defect.
Parity dashboard · one row per flow · each backed by a CI run
| Flow | Recorded on old | Replayed on new | Status |
|---|---|---|---|
| Create sample | Done | Done | Match |
| Assign tests to sample | Done | Done | Match |
| Enter raw results | Done | Done | Match |
| Approve result (QA) | Done | Done | Match |
| Issue certificate PDF | Done | Done | Defect → fixed → match |
| Customer portal login | Done | Done | Match |
| Monthly invoice run | Done | Done | Match |
| Export to accounting | Done | Done | Match |
| Audit trail per sample | Done | Done | Match |
A defect is not a surprise at go-live. It is a row on the dashboard until it matches.
Representative dashboard. Flow names are illustrative lab and ERP flows.
Guarantees
Four guarantees on every project.
- Typical 4–8 weeks
- Fixed price agreed before starting
- 100 % parity flow by flow
- Delay credit if we are late
If we are late for reasons attributable to us, we credit a fixed percentage of the rebuild price for every week of delay, up to a cap. The exact terms are written into the Blueprint proposal.
What we need from you
- Access to the running system and its data.
- One owner who can answer questions.
- About 2 hours a week of their time.
What you get
- The running system.
- The source code.
- The parity report.
- The runbook.
Every rebuild moves a legacy system onto the modern stack
Legacy system
PHP · old .NET / WebForms · VB6 · FoxPro
10+ years of users, data and email
ReStacking
built with Claude
- Next.js on Vercel
- Postgres
- Payload
- Clerk
- Resend
Same system, same users, same data. New technology underneath.
Coming next, productized: migration of Magento, WordPress and other PHP-based platforms (Drupal, Joomla, WooCommerce) to Payload on Vercel. Each migrator makes the next rebuild from that source faster and cheaper.
About platform migrations →Fractik
Every rebuild makes the next one faster.
Every project feeds Fractik, the method and platform behind every rebuild.
See whether your system fits.
30 minutes. We tell you whether a Blueprint makes sense.