Contract Software Engineer - Android, Voice & Video SDK at SendBird
Seoul, KR

The engineering team at Sendbird is solving the huge challenges building a reliable, feature-rich, and scalable real-time conversational experiences across different platforms.

The challenges range from building a platform that can reach a large user base across distributed environments with optimal latency, creating a feature-rich, yet lightweight and high performance client-side SDK, and building products and services that can help customers incorporate real-time conversational technologies more rapidly.

You will be participating in the Voice and Video SDKs team, enabling developers to build rich WebRTC-based media experiences. You are expected to learn and expand on your engineering expertise to build a world-class product that solves difficult problems of our customers, and make it easy for the customers to harness the power of real-time chat.

  • Design and implement key components of the Sendbird Android Voice & Video SDK
  • Build an efficient, lightweight, and high performance client side  Voice & Video SDK
  • Contribute to server and software architectures for real-time media streaming, quality optimization, and related systems engineering
  • Work with multiple other teams to build high-performance Voice & Video systems
  • Deep knowledge of Android with at least a year of experience developing, shipping, and maintaining mobile applications
  • Deep understanding of Android framework internals
  • Knowledge of general software design patterns as well as Android design patterns
  • Proficiency in Java with strong object-oriented design skills
  • Up-to-date on the latest framework changes, build tools, and libraries
  • Experience with Java multithreading and multi-threaded programming
  • Able to work independently and drive results
  • Ability to find the root cause of problems with a minimal set of information and only a few data points and understand the concepts of under-engineering and over-engineering
  • Professional experience and knowledge in building SDK
  • Experience in network programming (e.g., WebRTC, TCP/UDP, TLS, etc.)
  • Experience in Java, Kotlin, JVM, and NDK
  • Understanding and experience working with APIs. 
  • Wide range of experience from the front-end to the back-end
  • Experience in Unit testing and mocking
  • Experience in product design and architecture
  • Experience in learning and adopting latest technologies on Android platform
  • Awards from programming competitions (e.g., ACM ICPC, IOI, etc.)
  • English proficiency for business collaboration


Sendbird is the world's leading chat & messaging platform as a service. Our mission is to digitize human interactions for businesses. Our platform delivers billions of messages per month to help people connect through the products and apps they love.
We’re a Y Combinator alumnus (W16) and have raised over $120M from leading investors including ICONIQ Capital, Tiger Global Management, Shasta Ventures, August Capital, Techstars and FundersClub. We are headquartered in San Mateo, CA (50+ employees) with an Asia-Pacific office in Seoul (120+ employees).