I’m gearing up to launch a truly modular, multi-tenant backend and need a developer who has already walked this road at least once. The goal is not a marketing website but the underlying engine: cleanly separated services, tenant-aware data handling, robust auth, and an architecture that can welcome new feature modules without refactoring the core. You’ll be shaping everything from the database schema to the API layer and background jobs. Tech stack is flexible; the brief questionnaire captured “SaaS” rather than a fixed language, so I’m open to whichever stack—Node.js, Python, or Java—you can justify for long-term maintainability and scale. When you respond, focus on your direct experience building similarly modular or multi-tenant systems: what you built, the challenges you solved, and how the product is performing in production. Code samples or repo links where permissible are appreciated. Key deliverables: • A deploy-ready, tenant-aware backend (containerised or serverless is fine) • Clear module boundaries so new features can plug in without breaking existing tenants • Well-documented REST or GraphQL interface plus concise setup instructions I’ll review proposals based on demonstrated experience and clarity of approach, then we can drill into milestones, testing, and rollout strategy together. Looking forward to seeing how you’d architect this.