Senior C++ Developer

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 a global team of engineers dedicated to creating the best tools to ensure safe, convenient communication for millions of users worldwide. Our culture is built on innovation, teamwork, and a commitment to excellence.

We are seeking a highly motivated, self-directed C++ Developer with an entrepreneurial mindset to join our team. You should be a proactive problem-solver who takes full ownership of the communication infrastructure, acting as a force multiplier to accelerate our engineering velocity. This role focuses on client-server communication offering the opportunity to work on cutting-edge real-time communication systems and contribute to scalable, high-performance solutions. As a C++ Developer on our team, you’ll have the opportunity to impact millions of users daily by maintaining and enhancing infrastructure that handles over 50 million calls and 700 million messages every day, processing over 30 Gbps of network traffic. Your work will directly contribute to the reliability and performance of this high-traffic, mission-critical communication platform.

Responsibilities
Design and develop robust client-server communication systems using C++
Build and maintain VoIP server infrastructure components
Optimize performance for real-time communication applications
Collaborate with cross-functional teams to deliver reliable communication solutions
Debug and troubleshoot complex networking and communication issues
Participate in code reviews and maintain high code quality standards.
Requirements
At least 5 years of experience, proven track record with production C++ systems
Strong proficiency in C++ with solid understanding of modern C++ standards (C++17/20)
Experience with Boost libraries, particularly Boost.Asio for asynchronous I/O
Experience with client-server architecture and network programming
Knowledge of multi-threading, concurrency, and memory management
Understanding of networking protocols: TCP/UDP, RTP/RTCP, TLS/DTLS, and modern protocols (QUIC)
Experience with cross-platform development
Strong problem-solving skills and attention to detail
Understanding of security best practices in communication systems
Experience leveraging AI tools to enhance productivity or decision-making is a strong advantage.
Advantages
Java/Kotlin development experience
Understanding of JNI (Java Native Interface) for cross-platform integration
Real-time communication systems experience
SIP (Session Initiation Protocol) knowledge and implementation experience
WebRTC development and integration experience
Experience with audio/video codecs and media processing
Knowledge of VoIP protocols and standards
Familiarity with cloud platforms and containerization (Docker, Kubernetes)
Experience with performance profiling and optimization tools.