Telephony Engineer

Acclaim

1d•Remote

About The Position

We're expanding the team and are looking for a Telephony Engineer. The team has built award-winning AI products for tech corporations — devices, voice assistants, products that are actually in the world. We utilize a cutting-edge tech stack including Speech Technologies, NLP, Generative AI (LLMs, diffusion models), and a voice-first agentic architecture with privacy-first and on-premises deployment. We maintain a high engineering bar with real ownership, focusing on what works in production, and offer fast career progression due to a senior-heavy team and a high volume of real problems. This role offers a startup pace with enterprise stability, real clients, real revenue, and no bureaucracy.

Requirements

5 to 10 years of experience in VoIP and telephony engineering
Deep understanding of SIP protocol including messaging, methods, response codes and SDP, as well as troubleshooting of signaling and media issues including NAT and RTP
Knowledge of FreeSWITCH including architecture, dialplan development using Lua or XML, configuration of SIP profiles, gateways and modules such as ESL and Sofia, and performance optimization
Experience building utilities, tools, management services for VoIP infrastructure
Experience with Go language
Solid understanding of networking including TCP IP, RTP RTCP and traffic analysis using tools such as tcpdump, Wireshark and sngrep
Strong Linux administration (Debian or Ubuntu)

Nice To Haves

Experience with Kamailio/Opensips or rtpengine
Familiarity with CI CD, Docker, Ansible and Kubernetes
Experience with large scale telephony systems
Experience with Node.js for integration services, event socket (ESL) interaction with FreeSWITCH and REST API development
Background in voice biometrics projects

Responsibilities

Design and modernization of the telephony infrastructure
Integration with telecom providers in the US, LATAM and Europe
Optimization of resources and telecom costs
Building call handling systems from scratch for both outbound and inbound traffic
Development of integration solutions with the AI platform
Driving reliability, scaling and fault tolerance
Working with high call volumes using Kamailio/OpenSIPS and rtpengine
Participate in 2d and 3d level support duties as well as on-call rotation