Plumberium

How it is built

The storefront is a Next.js application talking to a Node API over a PostgreSQL database. Catalog pages are rendered on the server and cached at the edge so a contractor on a phone in a basement gets a page in well under a second; availability and account pricing are fetched client-side on top of that cached shell, because those are the two things that must never be stale.

The data model, in one paragraph

Everything hangs off four tables. Products carry the SKU, category, and dimensions. Inventory is a separate row per product per location, which is what makes drop-ship possible — the same SKU can be in stock at the branch and also available from the manufacturer with a different lead time. Accounts hold the contractor company, its ship-to addresses, terms, and price tier. Orders are immutable once submitted: subsequent changes are recorded as events against the order rather than edits to it, so the record still matches whatever the customer was told on the phone.

Why the cart is not a shopping cart

A consumer cart belongs to a person and dies when they close the tab. A trade cart belongs to a company, and often to a job. Ours persists against the account, can be picked up by a second person at the same firm, carries a PO number through to the invoice, and validates against account terms at checkout rather than taking a card. That single difference removes most of the phone calls the counter used to field.

Order routing

On submission each line is evaluated against the inventory table. Lines available at a branch are batched into a pick list. Lines that are cheaper or faster from the manufacturer are grouped into a purchase order and transmitted to that supplier, and the supplier's shipment confirmation flows back onto the same order. The buyer sees one order with one status; the fact that it left three different buildings is our problem, not theirs.

What we would build next

Quote-to-order for large jobs — a contractor bidding a building wants a priced take-off they can convert once they win.
Punch-out into the larger customers' procurement systems.
Returns and core charges, which are still handled at the counter.