What changes between a single-language Flemish boutique, a trilingual national retailer, and a cross-border DACH-focused merchant?

Three common Belgian shapes, three different builds:

• Single-language Flemish boutique (e.g. an Antwerpen-based fashion store serving Flanders only), one Magento store view in Dutch, no FR / DE needed. Bancontact + Payconiq are mandatory, Mollie covers everything. BTW templates only in Dutch. bpost shipping. Combell or Hyvä Cloud hosting. Audit + Build €5k, €10k total.
• Wallon-French boutique (e.g. a Liège / Charleroi store serving Wallonia only), one store view in French. Same payment stack. Watch for cross-border France traffic spillover, some stores add a fr_FR view to court French buyers.
• Trilingual national retailer (e.g. a Brussels-headquartered home-goods chain serving all of Belgium), three store views (NL + FR + DE), Peppol B2G ready (likely sells to schools / hospitals / municipalities), KBC + Belfius + ING + Bancontact + Payconiq + Klarna full stack, bol.com feed live. Build cost €15k, €40k, Enterprise tier likely.
• Cross-border DACH-focused merchant (e.g. an Eupen / German-speaking East Cantons B2B selling into DE + AT + CH), German-first store plus DE + AT + CH multi-currency / multi-VAT. Klarna + Sofort + SEPA primary, Bancontact secondary. Different shape entirely, we’ve done this with Liechtenstein- and Luxembourg-adjacent BE merchants.

Architecture decided in the audit step, the wrong shape costs €10k+ to undo later.