Capital Rx
Affordable Pharmacy Benefits, Powered by Modern Infrastructure.
Senior Machine Learning Engineer – SIP Telephony
Location
United States
Posted
7 days ago
Salary
$180K - $210K / year
Bachelor Degree6 yrs expEnglishAWSCloudEC2Open SourcePythonRust
Job Description
• Design, build, and operate greenfield SIP trunking infrastructure connecting carrier-grade telephony to our internal voice AI platform.
• Architect and implement real-time bidirectional audio streaming pipelines to support our ECS-based voice stack.
• Design autoscaling strategies for stateful, connection-based workloads, enabling the platform to scale dynamically based on connection ingress and concurrent call volume.
• Implement call routing, inbound/outbound dialing flows, and media transport (RTP/SRTP).
• Integrate with Amazon Connect to bridge carrier connectivity into our custom infrastructure.
• Collaborate with ML engineers, product managers, and other stakeholders to ensure the telephony layer meets the needs of our voice AI systems.
• Ensure outbound dialing infrastructure complies with TCPA regulations and supports STIR/SHAKEN attestation.
Job Requirements
- Minimum 6+ years of experience in software engineering with a strong focus on real-time communication infrastructure, telephony systems, or voice platforms.
- Deep hands-on experience with SIP protocol, including trunking, signaling flows, SDP negotiation, and RTP/SRTP media transport.
- Experience standing up and managing SIP trunks with cloud or carrier providers (Twilio, Bandwidth, Vonage, Telnyx, or similar).
- Experience building real-time bidirectional audio streaming infrastructure. - Proficiency with AWS infrastructure, including ECS (Fargate or EC2-backed), ALB/NLB, Kinesis, Lambda, and CloudWatch.
- Experience designing autoscaling strategies for stateful connection-based workloads (session scaling, concurrent call capacity planning).
- Experience with outbound dialing infrastructure, including familiarity with TCPA compliance and STIR/SHAKEN attestation.
- Strong proficiency in Python. Familiarity with C for working with open source telephony projects (FreeSWITCH, Kamailio, PJSIP, etc.) and Rust is a plus.