The latest articles on DEV Community by Julliette Hind (@zellq). https://dev.to/zellq https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F3864961%2F1261d47d-66da-4b28-8878-067760f6df5c.png https://dev.to/zellq en Julliette Hind Tue, 07 Apr 2026 05:31:49 +0000 https://dev.to/zellq/how-i-built-a-multi-tenant-b2b-wholesale-platform-with-nextjs-14-and-supabase-d90 https://dev.to/zellq/how-i-built-a-multi-tenant-b2b-wholesale-platform-with-nextjs-14-and-supabase-d90 <p>I spent the last few months building a complete B2B wholesale operating system from scratch. Here's a deep dive into the architecture and challenges I solved.</p> <h2> The Problem </h2> <p>Most small wholesale suppliers still manage orders over WhatsApp, email, and spreadsheets. There's no affordable tool built specifically for them. I set out to build one.</p> <h2> Tech Stack </h2> <ul> <li> <strong>Next.js 14</strong> (App Router)</li> <li> <strong>Supabase</strong> (PostgreSQL + Row Level Security + Auth)</li> <li> <strong>Stripe Connect</strong> (buyers pay merchants directly)</li> <li> <strong>Tailwind CSS</strong> + Framer Motion</li> <li> <strong>Resend</strong> (transactional emails)</li> <li> <strong>Vercel</strong> (deployment)</li> </ul> <h2> Architecture Decisions </h2> <h3> 1. Multi-Tenancy with Row Level Security </h3> <p>Each merchant gets their own store. Instead of separate databases, I used Supabase RLS to isolate data at the row level. This means every query is automatically scoped to the user's store — no middleware needed.</p> <h3> 2. Stripe Connect for Marketplace Payments </h3> <p>Buyers pay merchants directly through Stripe Connect. The platform takes a 2% fee per transaction. Each merchant onboards through Stripe's hosted flow — no API keys needed from their side.</p> <h3> 3. Pricing Engine </h3> <p>B2B pricing is complex. I built a pricing engine that handles:</p> <ul> <li> <strong>MOQ (Minimum Order Quantity)</strong> — products can require a minimum purchase</li> <li> <strong>Tier pricing</strong> — buy 10+ for $8, buy 100+ for $6</li> <li> <strong>Trade codes</strong> — VIP customers get custom discounts</li> <li> <strong>Per-customer price lists</strong> — override pricing for specific buyers</li> </ul> <h3> 4. Webhook System </h3> <p>For ERP/CRM integrations, I built a webhook system with:</p> <ul> <li>HMAC-SHA256 signed payloads</li> <li>Automatic retry (3 attempts with backoff)</li> <li>Delivery logs with status tracking</li> </ul> <h3> 5. Role-Based Team Access </h3> <p>Not every team member needs full admin access:</p> <ul> <li> <strong>Owner</strong> — full control</li> <li> <strong>Manager</strong> — orders + products</li> <li> <strong>Fulfillment</strong> — shipping only</li> <li> <strong>Read-only</strong> — view dashboard</li> </ul> <h2> What I Learned </h2> <ol> <li> <strong>Supabase RLS is powerful but tricky</strong> — one wrong policy and you either leak data or block everything</li> <li> <strong>Stripe Connect onboarding has edge cases</strong> — handle account deauthorization gracefully</li> <li> <strong>B2B UX is different from B2C</strong> — buyers want efficiency (list view, CSV upload, quick reorder), not pretty product galleries</li> </ol> <h2> Result </h2> <p>The platform includes:</p> <ul> <li>Buyer-facing storefront with cart, search, categories</li> <li>Full admin dashboard (products, orders, quotes, buyers, team, billing)</li> <li>Stripe payments + bank wire option</li> <li>REST API + webhooks</li> <li>Custom domain support</li> <li>Email notifications</li> </ul> <p>I packaged the entire codebase as a starter kit for developers who want to build similar B2B platforms: <a href="https://zellq.gumroad.com/l/b2b-wholesale-os" rel="noopener noreferrer">B2B Wholesale OS on Gumroad</a></p> <p>Happy to answer any questions about the architecture!</p> nextjs supabase webdev showdev