Developer for Multilingual Book Catalog Website + Google Sheets

We are looking for an experienced full-stack web developer to build a high-quality multilingual book catalog website for an independent publishing company. This is not a basic landing page or a template customization. The final website must be visually polished, responsive, reliable, easy for us to update, and capable of managing a catalog of more than 200 books. We have already prepared: * a navigable HTML prototype showing the desired structure, pages, style, and interactions; * a detailed PDF brief containing the final content, categories, navigation rules, visual references, and required changes. The HTML prototype is a starting point and visual/functional reference. The selected developer will be responsible for turning it into a complete, production-ready website. MAIN REQUIREMENTS 1. Multilingual and market-specific website The website will be available in five languages: * Italian * English * Spanish * German * French Each language version must have its own shareable URL. Changing the language must not only translate the interface: it must also display the specific book catalog for that market. The final texts and translations will be provided by us. 2. Homepage The homepage must follow the structure of the HTML prototype and the changes described in the PDF brief. It will include: * header and language selector; * hero section; * latest releases; * category navigation; * publishing approach section; * about section; * newsletter subscription; * footer. 3. Dynamic book catalog The catalog must display the books available for the selected market and allow visitors to filter them by category. Each book will belong to one of eight categories: * Children aged 1–3 * Children aged 4–6 * Children aged 6–8 * Children aged 8–12 * Teenagers aged 10–14 * Adults * Seniors * Couples/Gifts 4. Individual book pages Each book must have its own dynamically generated page containing: * cover image; * category; * title; * subtitle; * description; * market-specific Amazon purchase link; * “You may also like” section. The recommendation section must automatically display up to six other books from the same category, excluding the book currently being viewed. A “View all” button must open the catalog already filtered by that category. 5. Google Sheets integration We must be able to add, edit, or deactivate books without modifying the website code. The catalog must therefore be connected to a real Google Sheet containing one row per book. The data will include: * ID; * market/language; * title; * subtitle; * description; * cover image URL; * Amazon URL; * category; * publication date; * active/inactive status. When a row is added, modified, or deactivated, the website must update automatically without requiring manual code changes. The developer must recommend and implement a reliable, maintainable, and secure solution for this integration. 6. GetResponse integration The newsletter form must be connected to GetResponse and add subscribers to a list that we will provide. Email validation and clear success/error messages must also be implemented. 7. Privacy and cookies The project includes the creation and connection of the Privacy Policy and Cookie Policy pages, together with the necessary cookie consent management. 8. Custom visual elements The two temporary visuals contained in the HTML prototype must be replaced with two polished, high-quality visuals based on the references provided in the brief. The developer must present the proposed visuals for approval before their final implementation. 9. Future AI integration The website architecture must allow the future integration of Claude or other AI systems through APIs. The development of the AI assistant itself is not included in this project. FINAL DELIVERY The website must be: * fully responsive on desktop, tablet, and mobile; * fast and reliable; * tested across modern browsers; * ready for production and publication; * easy for us to maintain through Google Sheets. At the end of the project, we must receive: * the complete and working website; * all source code and project files; * all necessary administrative access; * deployment and configuration; * full ownership of the completed work; * clear instructions for managing the catalog through Google Sheets; * complete technical documentation for the website and its integrations. The work will be organized as a fixed-price project divided into milestones. Each milestone will be reviewed before payment is released. LONG-TERM SUPPORT AND MAINTENANCE We are looking for a developer who is interested in a long-term professional relationship and who will remain available after the initial launch to handle future technical problems, bugs, maintenance, compatibility updates, and improvements whenever required, including in the years following publication. Any bugs or incomplete functionality identified before final approval must be corrected within the original fixed price and at no additional cost. After final approval, future support, maintenance, updates, or additional work will be handled through separate paid Upwork contracts or milestones, with the scope and cost agreed upon in advance. The website must be built with clean, well-organized, and fully documented code. Complete technical documentation must be delivered so that the website can also be maintained by another qualified developer if the original developer is ever unavailable. HOW TO APPLY Please begin your proposal with the word “CATALOG” to confirm that you have read the full description. Your proposal must include: 1. Links to at least two relevant multilingual websites or dynamic catalog websites that you personally developed. 2. A brief explanation of your exact role in those projects. 3. The technology you recommend for this project and why. 4. How you would connect Google Sheets to the website reliably and securely. 5. How you would structure the five language-specific catalogs and their URLs. 6. Your estimated delivery time. 7. Your complete fixed-price quote. Generic applications and proposals without relevant working examples will not be considered.