This is the second stage of my CodeAlpha Full Stack internship — two projects, built in a deliberate order so the patterns from the first carry forward. First was a project management tool (auth + real-time updates with Socket.io). This one is a store: products, cart, orders. Same stack — Express, Prisma, PostgreSQL, JWT — but the interesting part isn't the CRUD, it's the order-placement flow, which is the first genuinely transactional piece of logic in the whole internship.
I'll walk through the schema decisions, the auth changes from project one, and then spend most of the time on the part that actually matters: making sure an order can never be created without correctly and atomically updating stock and clearing the cart.
The schema
model User {
id String @id @default(cuid())
