Chloéllia — Jewellery Commerce
A store for gold and fine jewellery, where no price is a stored number: the metal rate drives the catalogue, and a piece a customer specifies themselves is costed and assembled from its parts automatically.
Built at Davinda. Gold does not have a price, it has a rate, and the rate moves. A jewellery catalogue built on stored prices is wrong the moment it is saved — the shop either sells below cost or re-prices every item by hand each morning.
So the price is not a column. Every piece is described by what it is made of — metal, weight, purity, stones, the labour on top — and the price is derived from the current rate at the moment somebody asks for it. Change the rate and the whole catalogue is correct again, with nothing edited.
The same model carries the harder half. A customer specifying a piece of their own is not a special case to be quoted by hand: the custom order is assembled from the same components and costed by the same rules, so a piece that does not exist yet still has a price.
My part was the backend — the data model, the pricing rules and the REST API over them.