I’m building a retail-focused eCommerce ecosystem from the ground up with Next.js. The project will run several storefronts that all draw stock levels from one central warehouse while allowing different administrators to manage their own catalogues, orders, and promotions. Core architecture • 100 % custom code — no Shopify, Magento, WooCommerce, or other off-the-shelf engines. • Next.js on the front end with SSR/ISR for speed and SEO; you are free to suggest the best matching back-end stack and database so long as it scales cleanly across multiple stores. • A role-based admin area where Super Admin can create new stores, set permissions, and monitor global inventory, while Store Admins handle their individual storefronts. Must-have store features • Customer reviews tied to products, including moderation workflow. • Promotional banners that each store can schedule, target, and A/B test. Workflow expectations 1. Set up the multi-store framework and shared inventory logic. 2. Deliver one fully functional sample store that demonstrates the required features. 3. Provide clear documentation and hand-off so additional stores can be spun up without touching core code. Please outline the stack you propose, any relevant Next.js experience with multi-tenant applications, and an estimated timeline for completing the three milestones above.