Stays and rentals

Availability is harder than it looks because a stay is a range rather than a slot. Bookings cannot overlap, minimum-night rules vary by season, changeover days exist, and a gap of two nights between bookings may be unsellable. Pricing sits on the same structure — weekends, seasons, last-minute discounts, length-of-stay reductions — so the calendar is simultaneously an inventory system and a pricing engine, and both have to give the same answer to the question of what tonight costs.

Most hosts list on more than one platform, which makes calendar synchronisation a launch requirement rather than a later integration. The standard mechanism is a polled calendar feed, and polling means a window during which two platforms both believe a property is free. Closing that window as far as possible, and deciding what happens when a double booking does occur — because it will — is a policy decision the software has to encode before the first host arrives.

Trust is what makes a stranger sleep in another stranger's home, and reviews carry it. The mechanism worth building is double-blind: neither party sees the other's review until both are submitted or the window closes, which removes the retaliation that otherwise makes every review a polite four stars. Payouts matter for the same reason from the other side — a host who cannot see when money arrives, or who is paid late, stops listing, and hosts are the harder side of this marketplace to replace.