Job Title Senior Full-Stack Developer (Next.js/Postgres) – Build Multi-Tenant SaaS Marketing Suite (CRM, Email, SMS, Social) Job Description We are rebuilding desiforce.com, a multi-vertical directory (Real Estate, Events, Cars, Tutors), and expanding it into a SaaS platform. We need an expert developer to build a subscription-based marketing suite for our business users. Instead of building every engine from scratch, you will lead a "Buy & Integrate" strategy—leveraging powerful APIs and open-source tools to ensure high deliverability, compliance, and speed to market. Key Responsibilities: Infrastructure: Develop a scalable, multi-tenant architecture using Next.js (App Router), Postgres (RDS), and Prisma/Drizzle ORM on AWS. SaaS CRM: Integrate a "headless" or open-source CRM (e.g., Twenty.com or Erxes) to manage customer leads across different verticals. Omnichannel Marketing: Implement API-driven messaging: Email: Use Resend or Listmonk for high-deliverability transactional and marketing emails. SMS: Integrate Twilio or Infobip for automated alerts and marketing. Social: Implement Ayrshare or similar APIs to allow our users to post to FB, IG, and LinkedIn from our dashboard. Subscriptions: Build a tiered billing system (Basic vs. Pro) using Stripe Billing. Automation: Set up n8n or AWS Step Functions to automate workflows (e.g., "New listing triggers Social + Email alert"). Technical SEO: Ensure the platform follows best practices for SSR, ISR, and Core Web Vitals to maintain directory rankings. Required Skills: Frameworks: Next.js (Expert), React Server Components. Database: PostgreSQL, Prisma/Drizzle, Redis. Cloud: AWS (Lambda, RDS, CloudFront, S3). APIs: Twilio, Resend, Stripe, Ayrshare. DevOps: GitHub Actions, CI/CD, multi-tenant database sharding/isolation. Preferred Qualifications: Experience building SaaS MVPs or White-label platforms. Prior experience with open-source CRM or automation tools like n8n. Strong understanding of Technical SEO for large-scale directory sites. Need a database schema draft or a workflow diagram showing how you plan to handle "Multi-tenancy" (keeping User A's data separate from User B's data). This is the most critical technical challenge for your SaaS model.