Technical Product & Engineering Lead — Part-Time / Fractional

Quant Fusion is an early-stage B2B SaaS company building an AI-enabled order-to-cash orchestration platform for manufacturers and distributors. We are preparing to onboard our first production customer and need a senior technical leader who can help take the platform from MVP to scalable, enterprise-ready SaaS. This is not a typical developer role. We’re looking for someone who has helped build and take an early-stage SaaS product into production and can serve as a hands-on technical partner to the founder—writing code, making architectural decisions, and guiding technical execution. What You’ll Own • Strengthen the architecture as we scale to multi-tenant enterprise deployments • Personally contribute production-quality code while owning technical decisions across backend, database, APIs, enterprise integrations, security, and cloud infrastructure. • Troubleshoot production issues, implement fixes, and take ownership of deployment and operational reliability. • Improve engineering foundations including testing, CI/CD, environments, observability, and production reliability • Design and improve event-driven workflows, data ingestion, validation, and background processing • Help prioritize our AI roadmap and identify where RAG, agents, vector search, and other AI capabilities create real customer value • Mentor developers, review technical decisions, and help increase engineering velocity Tech Stack • Python / FastAPI • PostgreSQL • React + TypeScript • Google Cloud Platform • Firebase Authentication • Cloud Storage / Cloud Tasks / Pub/Sub / Cloud Functions / Dataflow • Claude Code and AI-assisted development Must Have • Proven experience building an early-stage SaaS product and taking it into production, ideally through subsequent growth and scaling. • Senior-level Python/FastAPI and PostgreSQL expertise • Experience with multi-tenant SaaS architecture • Strong cloud architecture experience, preferably GCP • Experience with event-driven systems and workflow orchestration • Strong security fundamentals: auth, tenant isolation, secrets, API security • Enough React + TypeScript depth to guide full-stack delivery • Daily use of Claude Code or comparable AI coding agents as a core development workflow Strong Plus • Hands-on experience designing, building, and maintaining API integrations between enterprise systems, including data synchronization, error handling, and reliability. • Manufacturing, distribution, ERP, WMS, supply chain, or order-management experience • Experience connecting multiple enterprise systems and orchestrating workflows across them • RAG, embeddings, vector search, Vertex AI, pgvector, AlloyDB, or Neo4j • SOC 2 or enterprise-security experience • Structured-data ETL / ELT pipelines Engagement • 5–20 hours/week initially • Remote • U.S. time-zone overlap preferred • Hourly engagement • Opportunity to expand responsibilities and hours as the business grows, with potential for a long-term technical leadership role. Please include brief examples of: 1. An early-stage SaaS company you helped scale 2. A workflow you built that connected multiple systems such as ERP, WMS, CRM, or similar 3. A SaaS architecture you personally designed or materially evolved 4. How you currently use Claude Code, Cursor, Codex, or other coding agents in your daily engineering workflow DIRECT FREELANCERS ONLY.. You must personally perform the work. NO AGENCIES, CONSULTANCIES, STAFFING FIRMS, OR DEVELOPMENT SHOPS. https://jobs.dover.com/Quant-Fusion/ef423cdd-923a-4565-a45b-1f33272f82b6?rs=15986553