Calendly works by asking the user to define a type of meeting, through a name, duration etc. and then to specify the time slots where such meetings can take place.
A booking page specific to this type of meeting is generated for other users to schedule a meeting with the user, taking into account the time slots and the user’s availability.
Calendly can take into account other rules like the maximum number of meetings per day or week of that type, or add a buffer time before and/or after a meeting.
Calendly has grown in popularity along the years, reaching more than 10 million users in 2020 making it a multi-billion dollar business.