Senior Full-Stack Engineer for Freight SaaS

We are looking for an experienced engineer to help cross the line from working prototype to commercial-grade SaaS — production infrastructure, code review, security hardening, and SOC 2 readiness. This is real work on a real product with real data. We are not exploring or experimenting. This platform is designed to be AI-native from the ground up — not AI bolted on after the fact. The system maintains a living knowledge base that accumulates signals from every user action, transaction outcome, and external data event. The goal is a product that gets meaningfully smarter every week — surfacing better recommendations, flagging risks before they materialize, and eventually acting autonomously on behalf of the user. The engineer we hire needs to understand this vision and help architect the data pipelines, feedback loops, and model integration layers that make it real. Tech Stack Frontend: React 18, TypeScript, Vite, custom CSS theming, hash-based routing Backend: Node.js, Express, TypeScript, compiled to CJS Database: SQLite (WAL mode) → migrating to PostgreSQL Query layer: Raw SQL via better-sqlite3 + custom storage layer Deployment: Moving to Render.com or Railway Integrations: 40+ Auth: Custom PBKDF2 token auth (no third-party library yet) Scale target: 200,000 users / 5M vendors, accounts, and orders What You'll Do Review codebase for security vulnerabilities, architectural weaknesses, and performance bottlenecks Lead SQLite → PostgreSQL migration — zero data loss, index design, connection pooling Set up production infrastructure (Render.com or Railway), CI/CD pipeline, and GitHub Actions Harden authentication — JWT or Auth0 migration, session management, rate limiting, secrets handling Implement structured logging, monitoring, and error tracking (Sentry or equivalent) Establish GitHub repo, branch strategy, and PR review process Prepare SOC 2 Type I readiness checklist and drive implementation Architect the AI feedback loop — data pipelines, learning systems, and model integration layers Advise on multi-tenancy architecture for future white-label / SaaS expansion Document architecture decisions, deployment runbooks, and onboarding guides Must-Have 5+ years Node.js / Express in production — deployed systems, not side projects Strong TypeScript across frontend and backend PostgreSQL — migrations, indexing, connection pooling (pg or Prisma) SQLite → PostgreSQL migration experience Production cloud deployment (Render, Railway, AWS, GCP, or Azure) CI/CD pipelines — GitHub Actions preferred REST API integration: auth patterns, rate limiting, retry logic, error handling Security fundamentals: OWASP Top 10, input validation, SQL injection prevention Auth0 or Clerk integration Multi-tenant SaaS architecture experience SOC 2 experience — Type I or Type II, startup environment preferred LLM integration (OpenAI, Anthropic, or equivalent) — prompt engineering, context management Vector database experience (Pinecone, pgvector, Weaviate) for semantic search and matching RAG pipeline experience — injecting structured data into LLM context at query time Feedback loop and learning system design — systems that improve on user behavior and outcomes Familiarity with agent frameworks (LangChain, LlamaIndex, or custom) for autonomous reasoning workflows