Demonstration project

A legacy warehouse system,
rebuilt with zero downtime.

A representative legacy system — old PHP, an exposed database, code that couldn't run on a modern server — modernized end-to-end. This is exactly the process I run for a real client, start to finish.

6/6
safety checks passing
100%
of behavior preserved
0
downtime to switch over
1
critical breach closed
01The system

A small warehouse ran its product list and staff login on software written over a decade ago. On the surface it worked. Underneath, it was a liability:

→Built on a version of PHP removed from the internet in 2015 — one server update from going dark
→A login wide open to SQL injection — anyone could log in as the owner, or steal the customer database
→Passwords stored in plain text
→Code, layout, and database queries tangled together — impossible to change safely
02What the audit found

The first step is always a free audit — a plain-English report of every risk, ranked by danger. Here's the summary:

Runs on removed PHP versionCritical
SQL injection in loginCritical
Plain-text passwordsHigh
No separation of concernsMedium
03The approach

No risky big-bang rewrite. A disciplined, five-step loop that protects the business at every stage:

1
Capture current behavior
Automated tests record exactly what the system does today — the safety net for everything that follows.
2
Rebuild the engine
A clean, modern, secure version is built — parameterized queries, hashed passwords, proper structure.
3
Prove nothing broke
The original tests run against the new version. Every one must still pass.
4
Close the holes
New tests prove the security flaws are gone for good.
5
Switch over safely
Traffic moves to the new system gradually, with instant rollback. No downtime.
04Proof: before → after

The same checks run against the old and new systems. The business-facing behavior is identical — the security hole is closed.

Check
Old
New
Products display correctly
✓
✓
Prices are correct
✓
✓
Real logins work
✓
✓
Wrong passwords rejected
✓
✓
SQL injection blocked
✗
✓
Old system — 4 / 5 · injection wide openNew system — 5 / 5 · breach provably closed
05Zero-downtime cutover

The new system went live behind a traffic switch. Customers used one address the entire time; traffic moved from old to new behind the scenes, with a one-second rollback on standby. Nobody using the system noticed a thing — which is the whole point.

Want to see what your system looks like?

The audit is free and takes 48 hours. You'll get this same kind of clear report on your own software — no cost, no obligation.

Request your free audit →