Senior VoIP / SIP Developer

This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Senior VoIP / SIP Developer based in Mexico. You will join an international technology project focused on building reliable and intelligent voice communication infrastructure. Your main focus will be developing an intelligent call-routing solution that integrates multiple telecom operators and optimizes routes based on cost, quality, and availability. The role combines backend development with hands-on SIP/VoIP infrastructure engineering in production environments. You will work across routing, failover, carrier integrations, and scalable telephony systems while contributing to solutions end to end. The position offers significant technical ownership, requiring autonomy and strong problem-solving skills across software and infrastructure. You will work with modern backend technologies, databases, containers, Linux systems, and cloud infrastructure in a fully remote environment. This is a full-time opportunity for an experienced telecommunications developer working on a technically challenging platform with international reach. Accountabilities - Design, develop, and maintain intelligent call-routing solutions for production SIP/VoIP environments. - Integrate multiple telecom operators and optimize call routes according to cost, quality, availability, and reliability. - Implement and maintain SIP routing, prefix-based routing, failover mechanisms, and related telephony logic. - Develop backend services and integrations using Python and/or Node. js/TypeScript. - Work with Kamailio or OpenSIPS to build and maintain robust SIP infrastructure. - Manage and optimize PostgreSQL databases supporting routing and telephony workflows. - Deploy and operate services using Linux, Docker, and cloud infrastructure. - Troubleshoot production issues across SIP signaling, routing, backend services, and infrastructure. - Take ownership of technical solutions from design and implementation through deployment and ongoing optimization. - Collaborate effectively in a fully remote, international environment while working independently on complex technical challenges. Requirements: - Proven professional experience working with SIP/VoIP in production environments.

- Strong hands-on experience with Kamailio or OpenSIPS . - Solid understanding of SIP, VoIP, call routing, prefix-based routing, and failover mechanisms. - Professional backend development experience with Python and/or Node. js/TypeScript . - Strong working knowledge of PostgreSQL . - Experience with Linux, Docker, and cloud infrastructure . - Ability to independently take ownership of technical solutions from conception through production. - Strong troubleshooting, analytical, and problem-solving skills. - Excellent autonomy and ability to work effectively in a fully remote environment. - English proficiency suitable for collaboration within an international technical team. - Experience with FreeSWITCH, Asterisk, LiveKit, rtpengine, Telnyx, Twilio, Plivo, or Bandwidth is highly valued. - Previous experience working with telecom carriers, CPaaS platforms, or telephony infrastructure is a strong advantage. Benefits: - 100% remote work arrangement. - Full-time employment. - Opportunity to work on an international technology project with real-world production telephony infrastructure. - High level of technical ownership and autonomy. - Exposure to advanced SIP/VoIP routing, carrier integrations, failover, and intelligent call-routing systems. - Opportunity to work across backend development, cloud infrastructure, Linux, Docker, and telecommunications technologies. - Challenging technical environment focused on building scalable and reliable communication solutions. - Opportunity to contribute to a project with international reach and significant technical scope.