I already rely on a detailed Excel payroll template that contains every calculation and lookup our team needs. Now I want those same capabilities available online so staff can run payroll from any browser without touching the spreadsheet itself. Key requirements • The app must be fully web-based and responsive. • Secure user authentication is mandatory—each employee should have a personal login, and I will need an admin role with elevated rights. • Users must be able to upload the current Excel file to seed or overwrite data, and download an updated version whenever they need an offline copy. • All existing worksheet formulas have to run in real time inside the app, so totals and deductions update instantly as values change. I’m open to the stack you choose—whether that’s React + Node, Django, Laravel, or another proven framework—as long as the final product is clean, maintainable, and easy for me to host. When you reply, let me know: 1. A brief outline of your proposed tech stack. 2. How you would reproduce the Excel logic in the browser. 3. Any similar projects you have completed. I’ll share the actual workbook after we agree on the approach, and we can iterate from there until every calculation matches the original sheet 1:1.