Backend Developer

Position SummaryOXUS Afghanistan is seeking an experienced Backend Developer to design, develop, and maintain secure, scalable, and high-performance backend systems that support the organization's digital transformation initiatives. The successful candidate will develop backend applications, build RESTful APIs, integrate databases and third-party services, implement business logic, and collaborate closely with UI/UX Designers, Mobile Application Developers, and other stakeholders to deliver secure, reliable, and enterprise-grade software solutions. Key ResponsibilitiesThe Backend Developer will be responsible for the following:Backend DevelopmentDesign, develop, and maintain secure, scalable, and maintainable backend applications.Develop RESTful APIs for web and mobile applications.Implement business logic based on organizational and business requirements.Write clean, reusable, efficient, and well-documented code.Participate in software architecture and technical design discussions.Database ManagementDesign, develop, and optimize relational databases (Microsoft SQL Server and/or PostgreSQL).Create and maintain database schemas, tables, stored procedures, views, and SQL queries.Optimize database performance through indexing, query optimization, and performance tuning.Ensure database integrity, reliability, backup, and data consistency.API Development & IntegrationDesign and implement secure RESTful APIs following industry best practices.Integrate third-party services such as payment gateways, SMS gateways, email services, authentication providers, and external APIs.Develop and maintain API documentation using standard documentation tools.Ensure proper API versioning and backward compatibility.SecurityImplement secure authentication and authorization using JWT, OAuth2, or similar technologies.Apply secure coding practices and protect applications against common vulnerabilities, including SQL Injection, Cross-Site Scripting (XSS), Cross-Site Request Forgery (CSRF), and OWASP Top 10 security risks.Implement logging, auditing, and secure handling of sensitive information.Performance & ScalabilityOptimize application performance, scalability, and reliability.Implement caching mechanisms where appropriate.Develop background processing services for long-running tasks.Monitor application performance and troubleshoot production issues.CollaborationWork closely with UI/UX Designers, Mobile Application Developers, QA, and business stakeholders throughout the software development lifecycle.Participate in code reviews and technical discussions.Contribute to software architecture, design decisions, and continuous improvement initiatives.DocumentationPrepare and maintain technical documentation, API documentation, deployment guides, and system documentation.Maintain source code using Git and follow established version control practices. Required QualificationsBachelor's degree in Computer Science, Information Technology, Software Engineering, or a related field.Minimum 3 years of professional experience in backend software development.Experience developing enterprise-level web applications and RESTful APIs.Strong analytical, problem-solving, and communication skills.Ability to work independently and collaboratively within a team. Required Technical SkillsProgramming & Backend FrameworksCandidates should have strong professional experience with at least one of the following backend technologies:ASP.NET Core (C#)PHP (Laravel)Java (Spring Boot)Python (Django / Django REST Framework)Node.js (Express.js or NestJS)Go (Gin or Fiber)Experience with multiple backend technologies will be considered an advantage.DatabaseMicrosoft SQL Server (Required)PostgreSQL or MySQL (Preferred)Database design and normalizationSQL query developmentStored procedures, views, triggers, and indexingDatabase performance tuning and optimizationAPI DevelopmentRESTful API developmentJSONHTTP/HTTPS protocolsAPI authentication and authorizationAPI documentation (Swagger/OpenAPI)Authentication & SecurityJWT AuthenticationOAuth2Role-Based Access Control (RBAC)Secure password hashing and session managementKnowledge of OWASP security best practicesVersion ControlGitGitHub or GitLabExperience with collaborative development workflows, including branching, pull requests, and code reviewsDeployment & InfrastructureIIS, Nginx, or Apache Web ServerWindows Server and/or Linux Server administrationDocker and containerization (Preferred)CI/CD concepts (Preferred)Additional Technical SkillsExperience with the following will be considered an advantage:Background job processing (Celery, Hangfire, Quartz.NET, or similar)Redis or other caching technologiesUnit testing and integration testingDebugging and troubleshooting production systemsLogging and monitoring toolsThird-party API integrationsAgile/Scrum development methodologiesPreferred CompetenciesStrong understanding of software architecture and design patterns.Knowledge of database optimization an...