We are looking for a Full-Stack Developer or Software Engineer with strong experience in building SaaS applications and integrating them with technical platforms (especially Salla). The candidate will be responsible for: Building and developing a fully integrated application connected to Salla–Zid Managing backend architecture Implementing technical integrations (APIs, OAuth, Webhooks) Designing and developing the Admin User Interface (Admin UI) Delivering a professional and practical user experience The role requires someone who is truly skilled technically and design-wise, capable of thinking and executing at the same time. Key Responsibilities Backend Development Develop the application using: Node.js + Express or PHP + Laravel Design and implement RESTful APIs within the application Manage databases (MySQL / PostgreSQL) Build business logic Write clean, scalable, and maintainable code Optimize performance and handle errors API & Integration Integrate the application with: Salla APIs External systems (CRM, payment gateways, marketing tools) Handle: OAuth2 (Authorization Flow) Access & Refresh Tokens Webhooks (customer creation, order completion, etc.) Manage real-time synchronization Process background jobs UI/UX Development Design and implement an internal Admin Panel Build interfaces using: HTML5 CSS3 JavaScript (ES6+) or modern frameworks such as React / Vue Translate requirements into a clear and smooth user experience Design a practical merchant-facing interface for: CRM rule configuration Conditional discount creation Reports display Focus on UX: Reduce complexity Provide clear options Deliver a professional experience Project Scope The developer will be responsible for implementing two main features: Within one application