Senior Telephony Engineer (Freeswitch) (USD 3.5- + equity)

We're looking for a Senior Telephony Engineer with deep expertise in telephony systems, SIP trunks, PBXs, and SBCs to lead our telephony infrastructure as the Head of Telephony at the company. You will be responsible for designing and implementing complete call center infrastructures from scratch, owning the architectural decisions, and mentoring the broader engineering team on telephony best practices. The role is focused on building and customizing flows using FreeSWITCH, integrated with APIs and cloud services.
Responsibilities
Lead the telephony engineering function: set technical direction, define standards, and own the roadmap for voice infrastructure.
Design, configure, and manage SIP trunks, PBX systems, and Session Border Controllers (SBCs) using FreeSWITCH and Kamailio.
Architect and implement call center flows end-to-end: IVR menus, call queues, agent routing, failover logic, and carrier redundancy.
Integrate telephony systems with cloud platforms and API...