Senior Full Stack Developer İş İlanı

Senior Full Stack Developer We are seeking a highly capable Senior Full Stack Developer to join our product-focused development team. The ideal candidate has strong backend expertise—particularly with Node.js, RESTful APIs, and MySQL —along with solid frontend experience using modern JavaScript frameworks. This is a hands-on engineering role requiring strong development skills, architectural thinking, security awareness, and the ability to design, build, and maintain scalable, secure, production-ready systems end to end. Responsibilities Design, develop, and maintain scalable backend services using Node.js . Build, document, secure, and maintain RESTful APIs used by web and mobile applications. Design and manage MySQL databases, including schema design, indexing, query optimization, migrations, data integrity, and performance tuning. Develop and maintain modern, responsive frontend applications using React.js and Next.js . Collaborate with product and design teams to translate business requirements into reliable technical solutions. Apply secure development practices throughout the software development lifecycle, following OWASP recommendations and industry security best practices . Design and implement secure authentication, authorization, session management, and role-based access controls. Protect applications and APIs against common vulnerabilities such as injection, XSS, CSRF, broken access control, insecure authentication, SSRF, and sensitive data exposure. Implement proper input validation, output encoding, error handling, rate limiting, and secure API design. Ensure secrets, credentials, API keys, and sensitive configuration are handled securely and are never exposed through source code, client applications, logs, or repositories. Identify and address security risks in application dependencies and third-party packages. Ensure application performance, security, reliability, and scalability across the stack. Review code and contribute to architecture and technical decisions. Participate in code reviews with a focus on maintainability, performance, and security. Troubleshoot production issues, identify root causes, and continuously improve system reliability. Required Qualifications 5+ years of professional software development experience , with demonstrated senior-level experience building and maintaining production systems. Strong expertise in JavaScript and Node.js , including asynchronous programming, API design, backend architecture, and error handling. Proven experience designing, building, and consuming RESTful APIs . Strong knowledge of MySQL , including: Database and schema design Writing and optimizing complex SQL queries Indexing and query performance analysis Transactions and data consistency Database migrations and production database management Solid professional experience with React.js ; experience with Next.js is highly preferred. Strong understanding of web application architecture and client/server data flow. Strong understanding of authentication and authorization , including sessions, tokens, permissions, and role-based access control. Practical knowledge of the OWASP Top 10 and secure web application development practices. Ability to recognize and prevent common security vulnerabilities, including: SQL/NoSQL injection Cross-Site Scripting (XSS) Cross-Site Request Forgery (CSRF) Broken Access Control / IDOR Authentication and session vulnerabilities Server-Side Request Forgery (SSRF) Security misconfiguration Sensitive information and credential exposure Understanding of secure password storage, cookies, HTTP security headers, CORS, TLS/HTTPS, API rate limiting, and input validation. Experience working with Git-based version control systems and collaborative development workflows. Ability to write clean, maintainable, testable, and well-structured code. Strong debugging and problem-solving skills. Ability to take ownership of features from technical design through production deployment and maintenance. Nice to Have Experience with mobile application development using React Native, Flutter, or native platforms . Experience building or maintaining high-traffic or data-intensive applications . Experience with automated testing, including unit, integration, and API testing. Experience with CI/CD pipelines and automated deployment workflows. Experience with Docker, Linux environments, reverse proxies, and cloud infrastructure . Familiarity with security testing tools, dependency vulnerability scanning, SAST/DAST , or penetration testing. Experience with application monitoring, structured logging, metrics, and production observability. Familiarity with caching, queues, background workers, and asynchronous processing. What We Are Looking For We are looking for a senior-level engineer who takes ownership , not simply someone who implements assigned features. You should be comfortable understanding the complete lifecycle of a production application—from database and backend architecture through APIs and frontend implementation to deployment, performance, security, and ongoing maintenance. You should be able to evaluate technical trade-offs, identify scalability and security issues before they reach production, contribute meaningfully to architectural decisions, review the work of other developers, troubleshoot complex production problems, and take responsibility for the quality of the systems you build.