VoIP Engineering Lead — Own the Production Call Path

Newfund; Seattle (WA); On-site; USD 175,000 - 195,000; Full time

Job summary

Tin Can is hiring a Senior VoIP Engineer to own the SIP and media plane that carries every call. You will manage Kamailio and FreeSWITCH deployments on AWS, implement dialplans, and ensure high-quality voice paths across carrier trunks and devices.

You’ll work hands-on with routing, tracing, and test scenarios, expanding to new markets while hardening TLS, SRTP, and call-security controls. Join a small, mission-driven team focused on safe, screen-free family communication.

Qualifications

• 5+ years building and operating real-time voice systems in production.
• Hands-on Kamailio and FreeSWITCH depth and SIP/RTP expertise.
• Experience debugging live calls from packet captures and SIP traces.

Responsibilities

• Own the production SIP and media plane end to end — Kamailio, FreeSWITCH, and carrier trunking.
• Review call-path changes and author SIP test scenarios before changes ship.
• Write and maintain Kamailio routing logic (dispatcher, registrar, usrloc, TLS).
• Build FreeSWITCH dialplans and integrations (ESL, mod_xml_curl, Lua).
• Provide packet-level call quality metrics (MOS, jitter, packet loss) and alert on issues.
• Model and load-test call capacity against peak traffic using real call flows.
• Extend SIP and media layer as we expand to new countries with different rules.
• Harden signaling and media paths (TLS, SRTP, rate limiting, STIR/SHAKEN).
• Improve team docs, runbooks, and code reviews for the voice stack.

Skills

Kamailio

FreeSWITCH

SIP

RTP

Packet capture

Troubleshooting

Documentation

Tools

rtpengine

Homer/HEP

Prometheus exporters

SIPP

Job description

Tin Can is hiring a Senior VoIP Engineer to own the SIP and media plane that carries every call. You will manage Kamailio and FreeSWITCH deployments on AWS, implement dialplans, and ensure high-quality voice paths across carrier trunks and devices.

You’ll work hands-on with routing, tracing, and test scenarios, expanding to new markets while hardening TLS, SRTP, and call-security controls. Join a small, mission-driven team focused on safe, screen-free family communication.