It's mostly CRUD, and the stack is very boring: Rails/Hotwire/Bootstrap, about 10k lines (we have apps for the staff on the ground, agents and agencies that we partner with, and some other stuff in there). The tricky part of handling the bookings is that on any given day we have a limited number of horses and multiple types of rides: 3 trails at 10AM, 1 trail at 3PM. A few times a month we'll max out the horses and not have availability for a given time. We can burst horsepower if we need to and accommodate bigger groups if we're hitting capacity and suspect load will maintain its current HPH. (that was a stretch; I tried)
We also track what horses have been used and how much so that we're not riding them into the ground — the people on the ground have an app I built in Framework7 to manage everything; they love it and Framework7 is very fun once you get rolling.
We ask for a 20% deposit to "hold [your] horses" and to prevent no-shows; the rest is transacted at the ranch (though we make the option to pay in full available if you email us). Our cancellation policy extremely flexible and though we say 24 hours on the site, we've never not refunded someone.