Location: Russia Work format: remote within the Russian Federation Grade: 2+ years of experience

Technology stack: FreeSWITCH, SIP, RTP/RTCP, sngrep, Wireshark, tcpdump, Homer, Linux, Golang (Go), VoIP, PBX, Contact Center, Highload, TLS, DNS SRV/NAPTR, PostgreSQL, Kafka, Redis, Kubernetes.

✔️Tasks: • Building and maintaining FreeSWITCH from source, implementing patches, developing/connecting custom modules. • Diagnosing and resolving complex SIP/VoIP incidents at all session levels (network/protocols/media/infrastructure). • Optimizing FreeSWITCH for high loads: performance, stability, fault tolerance. • Interaction with the microservice part of the platform (Golang), integration with internal services and buses. • Participation in building observability: metrics/logs/traces, call quality control, signaling/media monitoring.

✔️Requirements: • FreeSWITCH (core): ability to build from source for production (patches/modules), deep understanding of FreeSWITCH architecture; ability to read and analyze C code of modules for diagnostics and targeted modifications; practical experience in fine-tuning and optimizing FreeSWITCH for high loads. • VoIP (diagnostics): analyze SIP/RTP cases, confirm hypotheses with logs/traces, demonstrate in sngrep + tcpdump/Wireshark, use Homer/analog for retrospect. • Linux (platform): find and eliminate bottlenecks on the host (network/IO/CPU), understand the impact of OS settings on call quality and stability.

✔️Will be a plus: • Kubernetes (k8s): deployment and orchestration of services. • Experience with the project stack: Golang (microservices), PostgreSQL, Kafka, Redis. • Understanding of DevOps practices: CI/CD, monitoring, Infrastructure as Code.

✔️Company conditions: • Flexible employment options: Sole Proprietor, Civil Service, Civil Law Contract. • Well-thought-out onboarding system, mentor support, and transparent processes.

If you are interested in the vacancy, please contact me! @annanapreeva 🚀