What changes between an Istanbul textile exporter, Ankara local-only B2B, and a Trendyol-scale marketplace seller?

Three very different Magento builds:

• Istanbul textile exporter, B2B-heavy, multi-currency (USD/EUR primary, TRY domestic), FOB/CIF Incoterms, wholesale tier pricing (5/10/50/100-unit breaks), VKN-validated B2B-only accounts, e-Fatura via PDP, KDV 0% on exports with Gümrük Çıkış Beyannamesi, multi-language (TR + EN + AR for Gulf buyers), shipping integration with Aras Kargo / DHL / Aramex. Hyvä Checkout for fast PDP. Catalog: ~500-5,000 SKUs.
• Ankara local-only B2B, B2B industrial / construction / spare parts. Local fulfillment via Yurtiçi / MNG, no marketplace integration (sales are direct + tender-driven), heavy emphasis on VKN-validated company accounts, customer-specific catalogues + Net-30/60 payment terms, ERP integration (Logo / Mikro / Netsis) for inventory + invoicing, KDV 20% standard, e-Fatura mandatory. Catalog: 5,000-50,000 SKUs.
• Trendyol-scale marketplace seller, B2C-only, 80%+ of orders come from Trendyol / Hepsiburada / n11, Magento storefront is a small fraction (10-20%) but used for brand-building + repeat customers. Stock-availability and pricing automation is critical, one outdated SKU mis-sold on Trendyol is a 1-star review and a delisting. Repricing automation + competitor monitoring weighs more than checkout UX. e-Arşiv mandatory for every B2C order. Catalog: 1,000-100,000 SKUs.

We scope the audit to your specific shape on day 1, same Magento, very different architecture and module choices.