Firebase Functions

Serverless backend logic: run event-driven Node.js or Python code on Google Cloud infrastructure without managing a single server.

Firebase Functions (Cloud Functions for Firebase) is a serverless framework: it executes your backend code automatically in response to events. Your code, written in Node.js or Python, runs in a secure, managed Google Cloud environment. Use it to implement custom server-side logic, like sending a push notification via FCM when a new document is written to Firestore, or running a scheduled job with Cloud Scheduler. It scales automatically from zero to planet-scale, eliminating infrastructure management. Deployment is handled efficiently via the Firebase CLI using the `firebase deploy` command.

https://firebase.google.com/docs/functions