Staff Software Engineer
We are looking for a Staff Software Engineer to set the technical direction for our telecommunications platform. You will own the architecture behind how calls enter, move through, and leave our system: SIP signaling at the edge (Kamailio / OpenSIPS), media and call control (FreeSWITCH, Asterisk, RTPengine), the Python services that connect voice infrastructure to our AI inference pipeline, and the underlying carrier-facing integrations.
#LI-DNI
What you will 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 the telecom team (testing, load testing, code review, on-call)
- Mentor senior/mid engineers, raise the 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 of 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 a voice platform at 1,000+ concurrent calls (knows the difference 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, Russian at B2
- Location: any, except Russia and Belarus
Additional experience we value:
- Working with large-scale WebRTC systems (ICE, TURN, media servers)
- Working with RTPengine, Jitsi, or mediasoup
- Building low-latency AI voice pipelines (streaming ASR/TTS, barge-in)
- Implementing STIR/SHAKEN and robocall mitigation
- Handling voice compliance requirements, including SOC 2, HIPAA, GDPR, and PCI
- Designing multi-region active/active voice architectures
- Hiring and growing telecom teams
Why join us
At Mad Devs, you will join a company that values creativity, strategic thinking, and continuous improvement. You will work on projects that reach millions of users worldwide, alongside a strong and supportive team. Here, you will grow professionally, take on meaningful challenges, and contribute to products that solve real problems at scale.
Employees benefits
Flexible working hours
Remote-first culture
Long-term projects
Salary in dollars
Professional communities
Onsite business trips
Training budget
Paid conferences

Hi, I'm Ekaterina.
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