Luyuan L.

I turn messy data and manual workflows into working AI and SaaS applications. I build the full product: data ingestion and cleaning, backend APIs, a usable interface, authentication, billing, testing, and deployment. My main focus is B2B SaaS and AI-powered data products. This includes normalizing inconsistent source data, deduplicating records, tracking where facts came from, and turning the results into search, dashboards, reports, or an AI-assisted workflow. FrontageRadar is my self-initiated site-selection product for outdoor advertising teams. I built its data pipeline, React and TypeScript interface, map-based search, AI-assisted analysis, workspace workflows, reporting, and subscription integration. It shows how I take a specific business problem through to a deployed product. Financial systems are a second core area of my work. My paid Upwork experience includes an Interactive Brokers API contract for automated order conversion, with order-state reconciliation, failure handling, and paper-account testing. I also build Python market-data services, broker API integrations, WebSocket feeds, and monitoring tools. I focus on software correctness and verifiable behavior; I do not promise trading returns. My stack includes React, Next.js, TypeScript, Python, FastAPI, PostgreSQL, Supabase, Stripe, and cloud deployment. I work on clearly scoped fixed-price milestones, with written acceptance criteria, source code, focused tests, and setup and handover notes. Send me the main workflow, a sample of the data, and any existing designs or code. I can help define a practical first milestone. Communication can stay in Upwork messages, with written updates and recorded walkthroughs.