Join Our Back-end Engineering Team!

We are looking for Staff Software Engineer to set the technical direction for telecommunications platform. You will own the architecture of how calls enter, route through, and leave our system: SIP signaling at the edge (Kamailio / OpenSIPS), media and call control (FreeSWITCH, Asterisk, RTPengine), the Python services that bridge voice with our AI inference pipeline, and the carrier-facing integrations underneath.

What will need to do:

Own end-to-end telecom architecture: SIP edge (Kamailio/OpenSIPS), media & call control (FreeSWITCH), Python services bridging voice to AI, carrier integrations
Scale platform to 10,000+ concurrent calls with tight latency/SLOs
Design HA/disaster recovery: anycast SIP, active/active media, geographic failover
Set engineering standards for telecom team (testing, load testing, code review, on-call)
Mentor senior/mid engineers, raise technical bar
Define voice quality observability & SLOs (MOS, jitter, packet loss, latency)
Lead carrier strategy: SIP trunk vendors, redundancy, LCR, STIR/SHAKEN
Partner with AI/product to keep latency budgets honest

Requirements:

8+ years engineering, 4+ years in telecom/VoIP in production
Technical leadership: design docs, mentoring, cross-team decisions
Deep production experience with FreeSWITCH + Kamailio OR OpenSIPS (custom modules, routing scripts, at scale)
Strong SIP/RTP/SRTP/SDP/ICE; debug via pcap and SIP trace
Operated voice platform at 1,000+ concurrent calls (knows diff to 10k)
Strong Python; can work in Lua/Go/C as needed
Production integration with PSTN/SIP trunk providers (Twilio, Telnyx, etc.), DID management, LCR
Hands-on HA/failover for real-time systems
Production Kubernetes (GKE/EKS) and Terraform
Language Proficiency: English at B2-C1 level, Russian at B2 level
Location: any, except Russia and Belarus

It will be a plus:

WebRTC at scale (ICE, TURN, media servers)
RTPengine, Jitsi, mediasoup
Low-latency AI voice pipelines (streaming ASR/TTS, barge-in)
STIR/SHAKEN, robocall mitigation
Compliance: SOC2, HIPAA, GDPR, PCI for voice
Multi-region active/active voice
Experience hiring and growing a telecom team

Why Join us

At Mad Devs, you will be part of a company that values creativity, strategic thinking, and continuous improvement. You will work on meaningful projects that impact millions of users worldwide alongside a talented and supportive team. By joining our team, you will have the opportunity to make a real impact, grow your career, and contribute to developing cutting-edge solutions in the world of backend engineering.