Find another user of the application and show them on OpenStreetMap

Hello, I have an idea for my application but I would like to advise you on technical issues. I’m interested in combining Ionic with OpenStreetMap and finding other users of the application in my location (~15-30 km). What solutions would you choose in the stack of techniques (leaflet? etc), I ask about storing applications, data (postgress? a web application should also have access to data) and the way of integration? I’m a senior Front-end Developer but I have 0 experience in Ionic so please give me serious answers :slight_smile: