2. Constraints¶

2.1 Technical Constraints¶

Constraint	Rationale
Python 3.12	Mandated runtime for all backend services
FastAPI	Chosen web framework; async-first, OpenAPI out of the box
PostgreSQL	Single relational database; one schema per bounded context
React	Mandated frontend technology
REST/JSON	Primary API style between frontend and backend

Constraint	Rationale
Bounded context ownership	Each bounded context (Users, Posts/Timeline, Messaging) is developed and deployed independently
OpenAPI-first	Every service must expose an OpenAPI 3.x spec before implementation begins
No shared database tables across bounded contexts	Cross-context data access goes through APIs only

Convention	Detail
Code style	PEP 8, enforced via `ruff`
Branch strategy	GitHub Flow (feature branches + main)
Versioning	Semantic Versioning 2.0 for all services
Documentation	arc42 in Markdown, diagrams as PlantUML → SVG