Lovable Developer Needed for Simple Excel-to-Time-Series Prototype

I’m looking for a developer experienced with Lovable, React/JavaScript, and Excel/XLSX data to build a small financial-data prototype. This is intentionally a narrow proof of concept, not a full SaaS application. The prototype needs to: * Allow a user to upload an .xlsx workbook * Inspect the workbook dynamically * Identify available sheets and column/variable names * Identify likely date/time columns * Identify numeric variables that can be plotted * Display available variables in a dropdown or selector * Allow the user to select a variable and plot it as a time series * Continue working when a different workbook is uploaded with changed or renamed variables The most important requirement is that the variable names cannot be hard-coded. The underlying workbook structure will continue evolving. The application needs to inspect the uploaded workbook and determine what data is currently available. For example, if one workbook contains: Date Sentiment Article Count Cluster Score And another later contains: Date New Sentiment Momentum Score News Volume The application should discover those new variables automatically without requiring code changes. For this milestone, I do not need: * Cloudflare R2 integration * Authentication or login * Payments * User accounts * AI/chat functionality * Final branding * Complex financial functionality * Production infrastructure The goal is simply to prove: Excel workbook → dynamic variable discovery → variable selection → time-series visualization The project will live in my Lovable workspace and be connected to my GitHub repository. You will work as a collaborator rather than building the project under your own accounts. Preferred experience: * Lovable * React / TypeScript / JavaScript * XLSX / SheetJS or similar Excel parsing * Recharts or similar charting library * GitHub Deliverables: * Working Lovable application * Source code synced to my GitHub repository * Successful testing with two differently structured Excel workbooks * Short README explaining how workbook parsing and variable detection work * Short Loom/video demonstrating the prototype Acceptance test: I will upload the original workbook and confirm the available variables can be plotted over time. I will then upload a second workbook with renamed and/or additional numeric variables. The second workbook must work without modifying the application code. Please keep the implementation simple and maintainable. I specifically want to avoid over-engineering this proof of concept. When applying, please briefly answer: 1. How would you make the Excel variable discovery dynamic rather than hard-coding column names? 2. What JavaScript/TypeScript library would you use to read .xlsx files? 3. Have you built anything similar in Lovable involving uploaded files, dynamic data, or charts? 4. Can you complete this for $200 fixed price within 2–3 days? 5. Are you comfortable working inside a Lovable project and GitHub repository owned by me?