Senior Full-Stack Developer / SaaS Architect Multi-Tenant SaaS Platform

We are looking for a senior full-stack developer to help us build a multi-tenant SaaS platform for different types of businesses. The platform will allow each business to manage its website, online store, customers, products, inventory, payments, employees, orders and reports from one system. The platform must support multiple businesses on the same application. Each business will have separate data, users, settings and permissions. A user can manage multiple businesses. Each business can also have multiple branches, stores, warehouses, teams and cash registers. The system must be modular and configurable. We should be able to enable or disable features for a business based on its plan or industry. We also need custom fields, workflows, forms, dashboards, branding and integrations without changing the core system for every client. One important part of the project is the AI website builder. Users should be able to create websites with a visual editor, and AI should be able to create or update the same reusable sections and components. We also need a common API and integration layer for payment gateways, WhatsApp, email, SMS, fiscal systems, logistics and other third-party services. The first phase will focus on the SaaS foundation: tenant management, authentication, roles and permissions, business structure, module management, core APIs, security and the base architecture. Other features will be added in later phases. Our current technology direction is Next.js, React, TypeScript, PostgreSQL, Supabase, React Native and Expo, with Vercel and Cloudflare for the initial setup. We need someone who can handle both architecture and development, and who has real experience building multi-tenant SaaS systems. Please review the attached requirements before applying. Please include: - Similar SaaS projects you have built - Your role and responsibilities - Suggested architecture for this project - Availability