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.