Architecture Overview

High-Level View

The API repository is the backend service for Agora Tutoring. It exposes a GraphQL endpoint, processes business logic, connects to storage/services, and serves webhook endpoints.

Users / Frontend (Next.js)
          |
          v
   GraphQL API (Express + Apollo)
          |
          +--> MongoDB (core app data)
          +--> Redis (pub/sub, real-time support)
          +--> Firebase (auth-related services)
          +--> Stripe (billing webhooks)
          +--> SendGrid / Email services
          +--> Jira webhook integration

Runtime Entry Points

• index.js: starts the service, initializes database, binds to configured port.
• src/server.js: creates HTTP server, GraphQL endpoint, WebSocket subscriptions, and webhook routes.

Main Backend Layers

• src/api/: GraphQL schema, modules, resolvers, directives, scalars, and loaders.
• src/database/: models, validators, plugins, and DB startup logic.
• src/helpers/ + src/utilities/: reusable helper and utility logic.
• src/webhooks/: inbound handlers for external systems.

Why this structure works

• Domain modules keep GraphQL features grouped by business area.
• Loaders reduce repeated DB reads and improve resolver performance.
• Plugins centralize model-side behavior (e.g., related updates, hooks).
• Separate webhook handlers keep third-party logic isolated from core API paths.