Daily Excel Calculation App

I have an Excel file containing 1,000 unique ID numbers, each paired with a start date and an end date. Separately, there is a flat file that holds one monetary amount for every calendar day going back forty years, with the value increasing each day. What I need built within one week is a small web-based tool that will: • ingest the ID/date spreadsheet plus the 40-year daily data file, • locate the amount on the start date and the amount on the end date for every ID, • subtract the first figure from the second (and occasionally add small adjustments that I will specify), • write the results—ID, start date, end date, difference—into a fresh Excel file, and • automatically push that file to my website once the run is finished. Because the calculation must execute every day, the program should accept a simple daily trigger (cron, Windows Task Scheduler, or similar) and cope gracefully with new or amended rows. To keep the run dependable I also need: • Data validation that flags missing dates or mismatched IDs before processing, • Automated error reporting by email or log file whenever anything goes wrong, and • A way to pick or design alternative output layouts so the Excel report matches future formatting needs. A clean, browser-based interface is preferred—upload the two source files, hit “Run,” and see status/progress. Behind the scenes you are free to use Python (pandas, openpyxl), Node, or any other stack you feel is fastest to deliver, as long as the final package can be deployed on a standard shared host or VPS. Deliverables will be: 1. The complete source code with clear setup instructions, 2. A ready-to-run web front-end, 3. A sample run demonstrating accurate results for at least five IDs I will supply, and 4. Brief documentation covering the daily scheduler, error handling, and how to change the report format. If you have done similar ingestion-to-Excel automations, especially where a calculation must run on a schedule, I would love to see a short example. Let’s get this running smoothly within the week.

Project ID: 40246533