Widnia
Property developer · catalogue + admin panel
Every flat shows its price, its price history and its floor plan. Staff run the catalogue themselves; the law says the price history can never be rewritten, so the database makes that impossible.
- 100accessibility
- 100SEO
- 94speed
The problem
Since July 2025 developers in Poland must publish the price of every flat, keep the full history of every price change and hand that list to the state every day. The fine reaches 10% of turnover. A brochure site does not cover it: the company needs a catalogue its own staff run.
What I built
A catalogue that answers before the phone call. Price, price per square metre, floor plan with room areas, and the price history as a chart. Filters work even with JavaScript off, and the choice stays in the address, so a link can be shared.
A price history that cannot be rewritten. Every change is stored with a date and an author, and the database refuses to edit or delete those rows. That is the legal requirement, met technically rather than by promise.
A panel the team runs themselves. The owner changes prices, a manager only statuses and enquiries. Permissions are checked on the server at every action, and every change goes into a log. A separate sandbox lets anyone try the panel without a password.
A buyer's account. Sign in with Google, see your enquiries and their status, and have your details filled into forms automatically.
Result
Accessibility 100, best practices 100, SEO 100 and speed 94 on the published site. 160 automated tests and 19 browser scenarios run before every change.
