Mini Payments Core
A Spring Boot payments API for transfers, retries, and transaction state.
- Built an account-to-account transfer flow with an explicit transaction model.
- Used idempotency keys and optimistic locking to guard against duplicate processing and concurrent updates.
- Covered the API with unit and integration tests using JUnit, MockMvc, and Testcontainers.
- Ran the app and database with Docker Compose for quick local setup.
This project helped me explore transaction handling, concurrency control, testing, and local setup.