A product catalogue that holds its own

The range is deliberately small, which made it tempting to skip the plumbing. We did the opposite: variants, stock movements, order snapshots and server-side totals from day one. Prices and tax are recalculated on the server at checkout, so a saved browser tab cannot dictate what someone pays. Stock is reserved when the order is placed, and every movement is recorded against the variant. The catalogue can grow to hundreds of products without changing how any of it works.