Senior Full-Stack Dev — AI SaaS MVP (Next.js, LangGraph, TypeScript)

We're looking for an experienced full-stack developer to build MVP for a SaaS web application from scratch. The app connects a brand's data and context, then generates on-brand marketing content through multi-LLM agent pipelines, with credit-based billing or business contracts. What we need: - User authentication - File upload and cloud storage - LLM-powered generation (OpenAI / Anthropic APIs) - Image/video generation for on-brand visuals (Replicate / Stable Diffusion etc) - Multi-step AI pipelines / orchestration with structured outputs (LangChain/LangGraph) - Retrieval over user data or brand context (Vector DB / pgvector) - Background job processing and status updates - Stripe integration for billing - Admin dashboard - Responsive, modern UI Technical requirements: - Next.js frontend - Node.js / NestJS backend with REST API - PostgreSQL / MongoDB - Redis / queues - Docker deployment - CI/CD pipeline - AWS - Replicate / Stable Diffusion Important: - Clean, production-ready code with proper error handling - Rate limiting and security best practices - Structured logging & observability Please share examples of SaaS applications you've built, especially marketing/content tooling, LLM/AI integration.