Senior Telco Operations Engineer (VoIP/SMS)

Rakuten Viber is one of the most popular and downloaded apps in the world. Working with us provides a unique opportunity to influence hundreds of millions of our users and to be part of the journey that makes us a super-app. Our mission is to make people’s lives easier by enabling meaningful connections, from precious moments with family and friends, through managing business relationships to pursuing their passions.

We are seeking an experienced Senior VoIP/SMS Engineer to join our Telco Operations team . The team manages Viber's voice and messaging infrastructure at scale, including wholesale voice and SMS operations, user activation services, and anti-fraud systems. This role combines hands-on engineering with operational leadership, working across carrier partners, internal platforms, and cross-functional teams to ensure service quality and business continuity.

• 3+ years of hands-on experience in VoIP/SMS operations or telecom engineering

• Strong knowledge of SIP protocol, SMPP/HTTP messaging, and voice routing (Class 4/5 switches)

• Experience with network debugging tools: Wireshark, tcpdump, SIP trace analysis

• Solid understanding of TCP/IP, networking fundamentals (switches, firewalls, routers, LAN/WAN/VPN)

• Experience with carrier interconnections: trunk setup, capacity management, and partner onboarding

• Familiarity with voice/SMS billing and rating systems

• Proven ability to work in a ticket-driven support environment with SLA awareness

• Excellent written and verbal communication skills in English

• Strong interpersonal skills, able to communicate effectively with carriers, internal stakeholders, and cross-functional teams.