What changes for a Wien boutique vs DACH cross-border vs Tirol ski-seasonal store?

The architecture changes meaningfully across these three Austrian edge cases:

• Wien boutique (one shop, online + click & collect), single Magento store, AT only, EUR only, USt 20%. EPS + Klarna + PayPal + Apple Pay rails. RKSV-compliant POS integration if click & collect pays at the counter. Cookiebot for DSG-A. Hosting: A1 or Cloudways Frankfurt. Typical scope: 60-120 hours.
• DACH cross-border (AT + DE + CH, all serving B2C + B2B), three-store Magento (separate URLs or one domain + country selector), shared catalogue, per-country tax (USt 20% / MwSt 19% / MwSt 8.1%), per-country currency (EUR / EUR / CHF), per-country payment (EPS + RatePay / giropay + RatePay / TWINT + PostFinance). VIES validation for cross-border B2B. Mandatory: separate Impressum + AGB + Datenschutz per store. Typical scope: 250-450 hours.
• Tirol ski / outdoor seasonal (Innsbruck / Kitzbühel), AT or DACH, but with extreme December, March traffic spikes. Architecture must auto-scale: Adobe Commerce Cloud, AWS Frankfurt with auto-scaling groups, or Hetzner with horizontal scaling + Cloudflare. ImageMagick + WebP at scale for product catalogs of skis / jackets / boots. Often paired with rental-extension modules + multi-warehouse inventory (Innsbruck + Kitzbühel + Sölden). Typical scope: 200-500 hours, peak-season ops retainer.

We pick the right architecture in the audit phase, over-engineering a Wien boutique costs you, under-engineering a Tirol ski shop breaks December.