4. Solution Strategy

4.1 Fundamental Decisions

Goal	Strategy
Maintainability	Three bounded contexts as separate FastAPI applications, each owning its PostgreSQL schema
Performance	Async I/O throughout (FastAPI + asyncpg); feed aggregation via pre-computed read models
Scalability	Stateless API processes; horizontal scaling behind a load balancer
Security	JWT-based authentication issued by the Users context; validated by all other contexts
Developer experience	OpenAPI specs auto-generated by FastAPI; React frontend consumes typed API clients

4.2 Architecture Style

Modular monorepo deployment: all three bounded contexts run as independent FastAPI processes but are developed in a single repository. This allows independent scaling while keeping cross-team coordination simple at the current stage.

4.3 Key Technology Decisions

Decision	Choice	Reason
Web framework	FastAPI	Async, automatic OpenAPI, Pydantic validation
Database	PostgreSQL (one schema per context)	ACID guarantees, rich query support, familiar tooling
ORM / query layer	SQLAlchemy 2 (async)	Pythonic, supports async, works well with FastAPI
Migrations	Alembic	Standard tool for SQLAlchemy projects
Frontend	React + TypeScript	Type-safe UI, large ecosystem
Auth	JWT (RS256)	Stateless, verifiable across services without shared DB

4.4 How the Strategy Meets the Quality Goals

Quality Goal	How it is addressed
Availability	Stateless services allow restarts and rolling updates without downtime
Performance	Async handlers + connection pooling keep latency low under load
Scalability	Each context scales independently; no shared mutable state
Security	RS256 JWTs; each context validates tokens locally
Maintainability	Hard context boundaries enforced by separate schemas and API contracts