Short write‑ups of problems we hit running a real commerce operation and what we changed in the code because of them. No product announcements; just the reasoning.
Trade discounts are not "10% off with code". They are forty trigger types — quantity of a family, amount across a department, every nth order, first order, cartons, gifts, vouchers, customer‑exclusive deals — stacked, metered, re‑evaluated on every basket change, and written to every invoice line as an allowance you can audit. How aiku's discount engine works, why buy‑X‑get‑cheapest‑free counts the way it does, and the penny that float arithmetic tried to steal.
The group catalogue — 62,000 master products feeding 317,000 shop products across 34 open shops — is where a thing is described once and pushed to every shop that sells it, so that in theory one person at one desk can run the lot. Majors and minors for multi‑currency prices, a "follow the master" switch at three levels, the scalar column we are retiring because it silently mixed currencies, and a price cascade that ran for a month multiplying RRPs by pack size before a repair put 1,635 values back.