Telephony Engineer

This is a fully remote position, open to applicants in Portugal.

📋 Description

• Design and enhance the telephony infrastructure.

• Collaborate with telecom service providers in the US, LATAM, and Europe.

• Streamline resources and reduce telecom expenses.

• Create call-handling systems from the ground up for both outbound and inbound traffic.

• Develop integration solutions with the AI platform.

• Promote reliability, scalability, and fault tolerance.

• Manage high call volumes utilizing Kamailio/OpenSIPS and rtpengine.

• Engage in 2nd- and 3rd-level support responsibilities.

• Take part in the on-call rotation.

⛳️ Requirements

• 5 to 10 years of experience in VoIP and telephony engineering.

• Profound understanding of the SIP protocol, including messaging, methods, response codes, and SDP.

• Experience in troubleshooting signaling and media issues, including NAT and RTP.

• Familiarity with FreeSWITCH, Asterisk, or another B2BUA, covering architecture, dialplan development using Lua/XML/conf, SIP profiles, gateways, and modules.

• Experience in performance optimization.

• Proven experience in developing utilities, tools, and management services for VoIP infrastructure.

• Proficient in any programming language.

• Strong understanding of networking concepts, including TCP/IP, RTP, and RTCP.

• Experience with traffic analysis tools such as tcpdump, Wireshark, and sngrep.

• Strong Linux administration skills, particularly with Debian or Ubuntu.

• Experience working with the Go programming language.

• Familiarity with Kamailio, OpenSIPS, or rtpengine.

• Understanding of CI/CD, Docker, Ansible, and Kubernetes.

• Experience in large-scale telephony systems.

• Knowledge of ESL and Sofia.

• Experience with Node.js for integration services, event socket (ESL) interaction with FreeSWITCH, and REST API development.

• Background in voice biometrics projects.

🏝️ Benefits

• Fully remote position available across Europe.

• 21 vacation days plus public holidays and 5 sick days.

• Private English lessons provided via Preply.

• Opportunity to work on award-winning AI products for technology corporations.

• Access to a cutting-edge technology stack that includes Speech Technologies, NLP, Generative AI, LLMs, diffusion models, and voice-first agentic architecture.

• High engineering standards with genuine ownership.

• Accelerated career growth opportunities.

• Fast-paced startup environment combined with enterprise-level stability.

• Real clients and revenue generation with minimal bureaucracy.