The context
What did the system need?
Nova covered catalog, cart, coupons, checkout, stock, orders, wishlist, addresses, returns, and bilingual customer flows.
My role and the decision
Pricing, inventory, payment, and returns were separated into focused services. Checkout used transactions, row locking, stock validation, snapshots, inventory movements, and an idempotency key.
✓28 feature-test files / 143 backend tests
✓39 documented API operations
✓18 frontend unit tests
✓16 Playwright journeys across desktop and mobile
Transparency note
No confidential client data or unverified business metrics are shown. The focus is delivered scope and explainable engineering decisions.