B2B buying is not a cart and a card. A single order can involve a negotiated price list, a credit limit, a purchasing approver, a purchase order number, and a warehouse that has to confirm availability before anything ships. Consumer commerce platforms treat those as edge cases. We treat them as the system.
Our B2B ecommerce development work starts with the data model — customers, contracts, price lists, entitlements, stock — because that is what determines whether the storefront on top of it can be trusted. Once the model is right, the ordering experience, the portal, and the integrations all become tractable.
Every engagement is written up as an architecture document before a line of production code is committed, so the scope and the price are agreed in advance rather than discovered halfway through.