Senior Realtime Backend Engineer

What you can expect

You will architect high-performance C++ backend systems powering Zoom's AI-driven Contact Center platform. Working with distributed telephony infrastructure and real-time voice services, you will optimize session management and media handling at global scale. Your work will directly impact millions of customer interactions with 99.99% reliability.

We deliver cloud telephony infrastructure for Zoom's omnichannel Contact Center platform. Our team collaborates across engineering, product, and operations to build high-concurrency voice services. We exist to power seamless, AI-enhanced customer experiences at enterprise scale.

• Designing and optimizing distributed C++ backend modules that ensure 99.99% reliability and massive scalability for real-time voice traffic
• Developing and tuning open-source telephony engines (Free SWITCH) for session management, media handling, and protocol compliance across global clusters
• Building low-latency synchronization mechanisms using Redis and distributed technologies to manage real-time call states with cross-functional engineering teams
• Troubleshooting complex system bottlenecks including memory leaks, thread contention, and network latency to maintain high-concurrency performance
• Collaborating with logic and product teams to optimize the C++/Lua bridge and deliver business features with minimal overhead

• Communicate fluently in Mandarin to collaborate with distributed engineering teams across regions
• Demonstrate 5+ years of professional C/C++ development experience or equivalent practical experience in systems programming
• Master Linux systems programming including IPC, socket programming, I/O multiplexing (epoll), and asynchronous I/O
• Apply deep expertise in VoIP/real-time communication systems with protocols including SIP, RTP/RTCP, WebRTC, and voice codecs
• Use Redis for distributed locking, caching, and state management in high-concurrency production environments
• Contribute hands-on experience with Free SWITCH, Asterisk, or similar telephony engines
• Apply familiarity with Lua scripting or embedded logic engines for telephony applications
• Demonstrate experience with audio quality control strategies or AI/ML integration for voice services (ASR/TTS/NLP)

Our structured hybrid approach is centered around our offices and remote work environments. The work style of each role, Hybrid, Remote, or In-Person is indicated in the job description/posting.

As part of our award-winning workplace culture and commitment to delivering happiness, our benefits program offers a variety of perks, benefits, and options to help employees maintain their physical, mental, emotional, and financial health; support work-life balance; and contribute to their community in meaningful ways. Learn more information

Zoomies help people stay connected so they can get more done together. We set out to build the best collaboration platform for the enterprise, and today help people communicate better with products like Zoom Contact Center, Zoom Phone, Zoom Events, Zoom Apps, Zoom Rooms, and Zoom Webinars.

We’re problem-solvers, working at a fast pace to design solutions with our customers and users in mind. Here, you’ll work across teams to deliver impactful projects that are changing the way people communicate and enjoy opportunities to advance your career in a diverse, inclusive environment.

We believe that the unique contributions of all Zoomies is the driver of our success. To make sure that our products and culture continue to incorporate everyone's perspectives and experience we never discriminate on the basis of race, religion, national origin, gender identity or expression, sexual orientation, age, or marital, veteran, or disability status. Zoom is proud to be an equal opportunity workplace and is an affirmative action employer.

All your information will be kept confidential according to EEO guidelines.

We welcome people of different backgrounds, experiences, abilities and perspectives including qualified applicants with arrest and conviction records and any qualified applicants requiring…