What is Backend as a Service (BaaS)?

Backend as a Service (BaaS) is a cloud service model that provides ready-made backend infrastructure — databases, authentication, file storage, push notifications, and APIs — as managed services, eliminating the need to build and maintain backend server code. BaaS is the complement to FaaS in the serverless architecture picture. Examples: Firebase (real-time database, authentication, cloud storage, hosting), AWS Amplify (authentication, API, storage for web/mobile apps), Supabase (PostgreSQL database with REST/GraphQL API, authentication, storage), Hasura (instant GraphQL API over existing databases). A fully serverless application combines BaaS (managed services for standard backend capabilities) with FaaS (custom business logic), resulting in zero server management while maintaining flexibility for custom logic.