Job Description We are looking for an experienced backend developer to build a middleware script that connects a supplier API called PUBLIK API with our SaaS eCommerce platform OnPrintShop. Important We cannot modify the SaaS platform code. The solution must generate an Excel file compatible with OnPrintShop Bulk Import. Project Overview We need a server side script that: Authenticates with the PUBLIK API Fetches Products Product details Images Stock quantities Prices Maps the data into the official OnPrintShop bulk import Excel template Generates a ready to upload Excel file in xlsx or xls format We will manually upload the file into OnPrintShop. No frontend work required. Key Technical Requirements Server side implementation using Node.js, Python, or PHP Handle API authentication with token based login Fetch complete product catalog Proper handling of product IDs containing special characters such as L/XL Stock logic If stock equals 0 product must be inactive If stock greater than 0 product must be active Map pricing fields from API Generate Excel matching a strict multi sheet template with fixed columns Must support both Initial full import Future updates based on SKU Expected Deliverables Fully working script Configuration file for API credentials Excel generator aligned with provided template Logging system Documentation explaining how to run and schedule Example generated import file Nice to Have Experience with large product datasets over 5000 products Experience with Excel generation libraries Experience with API integrations and data mapping Caching and optimization for large API responses Project Scope This is a one time development project but may lead to future work such as additional supplier integrations.