As long as the host rents through Airbnb or Booking, the platform takes the money, collects the tax and keeps things in order. Then a loyal guest comes back, and the host would rather welcome them directly to avoid the commission. Everything the platform used to do without saying so now lands on them. Writing a compliant contract. Working out the tourist tax at the rate of their town, then paying it over. Producing an inventory report that will hold up against an insurer.

An honest inventory report asks for about a hundred fields per property. The condition of every surface room by room, and a list of everything it holds. Nobody fills it in fully, and on the day something breaks there is nothing to show the guest.

The host photographs the room, and the form fills itself in. The overall condition, the list of amenities and the nine detail sections arrive already filled, then the host corrects what is wrong.

Showing what the machine filled in

An inventory report is legal evidence, and the host is the one who signs it. After the analysis, the interface opens by itself every card it has just filled. So the host walks past each field before confirming.

The design work started with a decision map. Before a single line of code, I listed every question to ask the host and every branch the contract had to produce. The landlord can be a private individual, a company or an association, with or without an agent. Then come the premises and their equipment, the term, the rent, the deposit, the charges and the signature. Then the technical surveys, which depend on the date of the building permit.

That map served as the master plan. The host only ever sees a guided form. Their answers feed a dozen decisions gathered in one place, which drive what gets written in the document.

The tourist tax is worked out on the real figures for the stay, then carried straight into the contract handed to the guest, with the detail of the calculation. The host retypes nothing, and the guest can check.

The moment the wording blocked everything

The electronic signature comes in three European regulatory levels, known by their acronyms SES, AES and QES. That is the wording of the trade, and it was the wording of the interface.

Both testers got stuck in the same place. Neither could say which level to take for a holiday rental. An acronym says nothing about what it guarantees, nor when to use it. Yet that choice sets what the contract is worth in a dispute.

Each level now carries an everyday name and the situation that calls for it. The choice is made by reading the screen, with no knowledge of the eIDAS regulation. The badges alongside are the ones from the app.

A host photographs the property with a phone, often in light that works against it, shutters half closed and the ceiling lamp on in broad daylight. The listing suffers, and the host has neither the budget nor the wish for a photographer.

Lumen reworks the photo without touching the property itself. The guest has to recognize the room when they open the door.

The whole suite, in a demo

Photo enhancement is only one of the features. The video alongside shows them all at work on one property, in the order a host meets them.

Each one states its cost in credits before it runs.

I wrote a brandbook. It sets the logo and its clear space, the 2 typefaces, the palette and what each color means.

A badge always keeps a soft tone, light background, saturated text and a matching border, never a solid fill. Each status also shows its icon and its word, so the meaning arrives intact for someone who struggles to tell red from green.

The same system serves two audiences with nothing in common. A private host with two holiday rentals, and a property management company running six properties for four owners. The data hierarchy absorbs the gap, the host is linked straight to their properties, the management company goes through owners and residences. The interface itself does not split in two.