I have this step-by-step git repo to create the most maintainable Firebase Functions. [https://github.com/felipeosano/nestfire-example][1]

If you have a project created on console.firebase.google.com then just clone the repo and change the .firebaserc with your project id.

This repository uses NestJS and NestFire. NestFire is an npm library that allows you to deploy Nest modules to Firebase Functions. This npm library also allows you to create fast and maintainable triggers. I recommend reading the documentation in its repository.