Telephony Infrastructure Engineer
$200k - $300k • SF Headquarters • FullTime
Posted 21d ago
About the job
Salient is seeking a Telephony Infrastructure Engineer to take ownership of the voice platform that powers our AI agents. This role involves managing the SIP edge, Asterisk, voice audio and dialing layers, and call servers. You will collaborate with AI agent engineers, telephony specialists, customer success teams, and carriers to ensure the platform's reliability, safety, and scalability for future growth. This is a hands-on position where you will complete ongoing projects, enhance platform stability, and prepare it to handle significantly increased call volumes. Additionally, you will design and implement customer telephony integrations, working towards making these processes more self-serve.
Responsibilities
- Complete the Asterisk migration, including cutting over remaining customers, trunks, and call flows without regression, and retiring the legacy path.
- Ensure the reliability of the voice audio and dialing layers through SLOs, monitoring, incident response, and eliminating recurring failure modes.
- Implement zero-downtime call-server deployments, including draining, graceful shutdown, safe rollout, and rollback without dropping live calls.
- Build tools to manage Kamailio and Asterisk reconfiguration within Kubernetes without server restarts.
- Develop backpressure, load shedding, and self-recovery mechanisms for degraded carrier, media, or AI dependencies.
- Conduct load testing and capacity planning to validate thousands of concurrent calls and CPS at the SIP edge.
- Enhance voice observability with call-quality and platform-health metrics, alerting, runbooks, and postmortems.
- Secure the voice edge against scanning, toll fraud, and abuse.
- Manage customer telephony integrations, including custom SIP trunks, call transfers, SIP header passing, and API prototypes with new contact-center platforms.
- Develop self-serve setup capabilities, including productized trunk configurations, validation tooling, and documentation to reduce time to go live.
Requirements
- Experience running production voice infrastructure at scale and being on call for it.
- Deep understanding of SIP, SDP, and RTP, with the ability to debug from traces and pcaps.
- Ability to debug EC2/K8s networking issues causing dead air and develop monitoring/testing plans to minimize it.
- Understanding of real-time media, WebRTC, and latency budgets.
- Experience designing for backpressure, graceful degradation, and safe deploys of stateful services.
- Experience building load tests that identified real bottlenecks before customers did.
- Proficiency in writing clear design docs, runbooks, and postmortems.
- Experience integrating SIP trunks with customer contact centers and carriers, including transfers and header passing.
Benefits
- Medical, dental, and vision coverage
- Generous 401(k)
- Catered lunches