Custom Web-Based Progressive Web Application (PWA) for Quotation, Sales & Payment Management IMPORTANT – PLEASE READ CAREFULLY This project must be developed on our company website / server. The system must be self-hosted 100% ownership of source code, database, and logic belongs to MODA Windows & Doors No SaaS, no subscriptions, no third-party quotation systems No licensed platforms that limit ownership Full access to code and deployment credentials is required If you cannot deliver a fully custom and self-hosted solution, please do not apply. Project Description We are looking for an experienced developer or development team to build a custom web-based Progressive Web Application (PWA) for: Quotation creation Sales management Payment tracking The system will be used internally by our sales team and admin, and must be secure, scalable, and easy to use. Development will be done step by step, starting with quotation and pricing features, and expanding later. User Roles Admin Full system control Create, edit, deactivate sales users Create and manage all price lists Define material, glass, mosquito net prices Define color surcharges and system surcharges Set discount limits per salesperson Manual pricing for special constructions View and export all quotations and payments Access all reports Delete records only with security code (no bulk deletion) Manage languages, backups, and system security Sales User Create and edit quotations Add window/door items Upload bank slips, photos, and warranty documents View only their own quotations and statistics Track quotation status, payments, and balances Sales users cannot: Edit price lists or pricing logic Delete records Access other users’ data Quotation Rules Each quotation has one fixed material and one fixed color Material and color are selected once Changing material or color requires a new quotation Old quotations remain archived and unchanged Editing a quotation generates a new quotation number Materials & Colors Materials uPVC Standard Aluminium Semi-Euro Aluminium Euro Aluminium Colors White (base price) Black (surcharge) Sahara / Bronze (surcharge) Wood finish (highest surcharge) Item Configuration (Windows & Doors) Each quotation may contain multiple items (W1, W2, D1, etc.). Each item includes: Mandatory drawing / schematic image Quantity (identical items only) Width & height (mm) Pricing calculated per square meter (m²) Opening Types Fixed Opening (in / out) Sliding Double opening Fixed + opening Glass Options 6mm, 8mm, 10mm Double glazing Laminated Frosted / clear / green Mosquito Net Options None Hinged Sliding Pleated Security stainless steel Pricing Logic All pricing based on m² Different base prices for fixed, opening, sliding, and doors Quantity automatically multiplies price Discounts limited by salesperson permission Manual pricing allowed for admin only Delivery Cost Calculated by distance (kilometers) Price per kilometer set by admin Automatically added to quotation total Payments & Status Quotation statuses: Quoted Deposit Paid Closed Finished Supports partial payments, for example: 40% advance 30% during production 30% on delivery Sales users upload bank transfer proof. Documents & Security Upload bank slips, photos, warranties Files visible only to uploader and admin Deletion requires security code Weekly automatic backups Non-editable PDF quotations, invoices, and receipts Additional Features Search quotations by customer name, phone, address, quotation number Store Google Maps / GPS location per quotation Multi-language system: English (master) Thai, Russian, Chinese, Greek, Turkish, Korean English shown first, translation below Out of Scope (Future Phase) Accounting & VAT automation ISO 9001 audit trail Warehouse & production modules Dealer / partner access ERP integration Who Should Apply Please apply only if you: Have experience building custom web applications or PWAs Understand pricing logic and role-based permissions Can deliver clean, documented source code Agree to full ownership transfer Can work with milestone-based payments