Appointment reminder bot for clinics and salons

We are looking for a developer to build an appointment reminder bot for our network of clinics and beauty salons. When a client books a visit, the system should automatically send a confirmation and then remind them a day before and a couple of hours before the appointment. If a client wants to reschedule or cancel, they should be able to do it right inside the chat, without calling the front desk or waiting for an operator to reply. The bot must work through popular messengers and SMS at the same time, keep track of the free time slots of every specialist, and suggest the nearest available dates when a booking is moved. It is important that notifications arrive on time and are never duplicated, and that cancelled slots are released immediately for other clients. We also need a clear admin panel where staff can see the schedule, confirmation statuses, and the full message history. We expect integration with our current booking system and flexible reminder texts tuned for each branch separately. Please tell us which platforms you have worked with, show examples of similar bots, and propose an implementation plan with an estimate of timelines and delivery stages. We will discuss the budget and the remaining details after a short call.