Title: Developer Needed to Build GST Calculation & Invoice Tool Description: I need a web-based GST calculation tool. The system should convert B2B and B2C Excel sheets into GST Tax Invoices with automatic GST calculation and clear display of all invoice details. The tool should offer functionality and workflow similar to commonly used online GST calculation platforms. Features Required: 1. Upload Excel files (B2B & B2C formats) 2. Automatic data extraction and field mapping 3. GST calculation (5%, 12%, 18%, 28%) 4. GST Tax Invoice generation 5. Display complete invoice details on a web page 6. Download options: ◦ PDF Invoice ◦ Excel summary 7. User login system (optional) 8. Admin panel to manage users and files (optional) 9. Clean, responsive UI/UX 10. Validation checks for duplicate invoices, missing HSN codes, and incorrect data Tech Preference: Any modern stack such as PHP/Laravel, Node.js, Python (Flask/Django), or equivalent. What I Will Provide: • Sample B2B/B2C Excel files • Required invoice format • Logo, themes, and branding Deliverables: • Fully working web application • Complete source code with documentation • Deployment support (cPanel / Cloud / Shared hosting) Budget: Open to best offer Timeline: 7–15 days