We are seeking a Full Stack Software Engineer to join our team on-site in Nagpur, India . In this role, you will work on DentTracks – a dental practice management platform with integrated VoIP communications – using FreeSWITCH and FusionPBX (open-source VoIP PBX built on FreeSWITCH alongside modern web (React.js, Node.js) and mobile app technologies. You will be responsible for the entire development stack: from configuring and optimizing our VoIP telephony systems to building user-friendly web interfaces and a companion mobile application. This position is ideal for a mid-level developer with a blend of VoIP expertise and full-stack development skills, looking to build innovative features in a dynamic environment. Key Responsibilities VoIP System Development: Install, configure, and maintain our FreeSWITCH/FusionPBX-based telephony platform, and implement call routing, IVR, and other VoIP features to support DentTracks’ communication needs. Back-End Development: Build and maintain server-side logic and APIs using Node.js (e.g., Express.js), integrating the VoIP system with application servers and databases. Ensure scalable and secure back-end services for features like call management and data processing. Front-End Development: Develop responsive web user interfaces in React.js (with HTML/CSS and TypeScript) for the DentTracks platform. Create intuitive dashboards and controls for users to interact with telephony features and other application modules. Mobile and Desktop App Development: Design and develop a mobile application for Android/iOS (using React Native or native frameworks) as a companion to the DentTracks web platform. Ensure seamless integration of mobile app features (e.g. VoIP calling, notifications) with the backend and FreeSWITCH/FusionPBX systems. Ensure inbound DID numbers are passed via SIP/WebRTC to the web application in real time. Develop a desktop dialer application integrated with FusionPBX (agent login, inbound/outbound calls, call controls). Performance & Troubleshooting: Monitor system performance and call quality across the VoIP infrastructure and web/mobile applications. Troubleshoot and resolve issues related to SIP signaling, audio quality, or application bugs to ensure high availability and reliability of the platform. Collaboration & Deployment: Work closely with other developers and stakeholders to integrate new features and improvements. Participate in architectural discussions, and assist in deploying updates (including configuration changes in FusionPBX or Node.js services) following best practices for version control and CI/CD. Requirements & Qualifications Education: Bachelor’s degree in Computer Science, Engineering, or a related field (or equivalent practical experience). Experience: ~3+ years of professional software development experience, including hands-on work with VoIP or telephony systems. Experience with FreeSWITCH and FusionPBX in a production environment is required. VoIP Skills: Solid understanding of VoIP protocols and networking (e.g. SIP , RTP ) and ability to configure PBX features. Familiarity with Linux server environments for managing telephony services. Front-End Development: Proficiency in front-end development using React.js (with JavaScript/TypeScript), and a good grasp of web technologies (HTML5, CSS3). Ability to create responsive, user-friendly interfaces. Back-End Development: Strong skills in back-end programming with Node.js , building RESTful APIs and services (Express or similar). Experience integrating with databases (e.g. MongoDB or SQL databases) for application data storage and retrieval. Mobile Development: Experience in developing mobile applications for Android and/or iOS . Exposure to cross-platform frameworks like React Native (or Flutter) is highly desirable for accelerating mobile development. Problem-Solving: Excellent debugging and problem-solving abilities to diagnose issues across the full stack – from voice call quality problems to front-end bugs. A proactive attitude toward learning new technologies and tackling challenges. Communication: Good communication and teamwork skills. Ability to work collaboratively in a fast-paced development environment and clearly document/communicate technical ideas and issues. Location Commitment: Must be willing to work on-site in Nagpur, Maharashtra. (This is an in-office role, not remote, so the candidate should be currently in Nagpur or willing to relocate.) Preferred (Nice-to-Have): Familiarity with other telephony platforms like Asterisk (PBX), and experience deploying VoIP solutions in cloud environments (AWS, etc.). Knowledge of WebRTC and secure VoIP practices (TLS, SRTP) is a plus.