ADR 0001: Use Modular Monolith

Status

Accepted

Context

The project is a portfolio backend intended to show senior engineering judgment. A microservice architecture would add deployment, networking, data consistency, and observability complexity before the domain requires it.

Decision

Use a modular monolith: one Spring Boot application composed from Maven modules with explicit package boundaries and ArchUnit tests.

Consequences

Benefits:

• simple local and CI execution
• clear ownership without distributed-system overhead
• refactorable boundaries while the domain evolves
• easier end-to-end testing

Trade-offs:

• module boundaries rely on code structure and tests, not process isolation
• all modules share one runtime and one database
• future extraction requires deliberate contracts and migration planning