The problem
The prototype stored everything in one browser. Data was lost when the browser was cleared, anyone with the file could see salaries and margins, simultaneous saves overwrote each other, and nothing recorded who changed what.
What I built
- Daily activity entry for each salesperson, split into new and existing customers: calls, connects, leads, follow-ups, quotations and orders.
- Invoices where the server works out cost and margin, so it is never typed in by hand.
- A dashboard, conversion ratios against benchmarks, analytics, daily and monthly P&L, and printable reports with ten charts.
- Settings, masters and user administration, and two companies in one system.
Security and trust
- Four roles (admin, manager, staff, viewer) enforced in both the PHP API and the database, so staff never receive margins or salaries.
- An audit log of every create, update and delete.
- Saves that stay safe when two people work at once, money stored as exact decimals, and impossible dates rejected.
How I checked it
- A large automated test suite for security, business rules and figures.
- A reference calculator, the SQL and the screen are checked against each other, so all three give the same numbers.
- Twelve monthly workbooks from the client (six months, two companies) were loaded and the figures compared with their own.
- Independent review rounds before launch found and closed critical issues, including a stored XSS.
Delivery
The system runs on the client's own server over HTTPS. Every release ships with a one-line way to undo it.
This is a private client system, so there is no public link or screenshot. The picture on the home page is an illustration with no client data.