In this chapter, we will write an API that allows users to go for a coffee! This comprises of a simple yet extendable user matching system.

Initially, we'll just ask the user to enter their name and e-mail, which is stored on MongoDB. Whenever we can match these with the nearest other user, e-mails are sent to both sides and then it's coffee time. After we set up the base, it's time to make sure we keep a record of the matches and avoid duplicates from happening for a better user experience.

Soon after, let's make ourselves ready to go global and take into account their geo positioning.

Assuming everything goes well (which is a mistake), we are validated. So it's time to refactor to a more maintainable architecture, where the pairing becomes a service by itself.

Finally, let's allow our users to rate how their meeting was and tell us whether it was a successful meeting or not in real-world applications, the usage of user generated feedback is invaluable!

We expect...