Appointy Associate Software Developer interview questions

Firstly they shortlisted candidates on the basis google form and there were two rounds first one was the Task round and the other was Personal Interview. In the Task round there were two tasks one for frontend and other for backend you to choose and build it. Basically the task was to build an API which gives the available slots of time for appointment. They had provided some APIs for resources and I have to make an algorithm that calculates the available time slots give it back as api response. And important thing the preferred language for backend was Go language.