Chat API for mobile apps and websites.

Software Engineer - Platform Team at SendBird

$100k - $160k / 0.00% - 0.25%
400 1st Ave, San Mateo, CA 94401
Job Type
3+ years
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About the role

At SendBird, we are building the most scalable and powerful chat API in the world. We have customers from over 150 countries and serve a wide-range of use-cases across communities, marketplaces, on-demand services, games, and e-commerce. After graduating from Y Combinator in Feb 2018, we raised a $16M series A round led by Shasta Ventures and August Capital and have become one of the fastest growing startups in Silicon Valley.

We are headquartered in San Mateo, CA and have an APAC office in Seoul, South Korea.

The engineering team at SendBird is solving some of the biggest challenges related to building reliable, feature-rich, and scalable real-time conversational experiences across different platforms. The challenges range from building a platform that can scale to some of the largest user-bases 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.


  • Build a large scale distributed and scalable real-time messaging service
  • Design simple, intuitive API to solve complex architectural problems
  • Write customer-centric documentation on API and messaging services
  • Architect and build efficient servers on our globally distributed infrastructure
  • Deploy and operate server clusters within a cloud environment


  • Working knowledge of Java or Python with at least 2 years of experience developing, shipping, and maintaining real-time systems
  • Have deep understanding of multi-threading and high performance distributed architecture
  • Able to work independently and drive results
  • Ability to find the root cause of problems with a minimal set of information and data points
  • Ability to find the optimal solution given the resource constraints, and understands the concepts of under-engineering and over-engineering


  • Experience working on a real-time chat/messaging system
  • Experience handling massive concurrent connections and processing large-scale traffic
  • Understanding of Unix/Linux systems
  • Understanding of Python, Java, and Event-Driven Frameworks
  • Understanding of TCP/IP and network programming
  • Understanding of RDBMS, NoSQL and distributed databases
  • Understanding of server virtualization, global infrastructures, load balancing, and handling massive data traffic
  • Awards from programming competitions (e.g., ACM ICPC, IOI, etc.)

Why you should join SendBird

SendBird is the world's leading chat & messaging platform as service backed by Shasta Ventures, August Capital, ICONIQ Capital, Tiger Global Management, and Y Combinator and have closed $102M Series B recently. We provide managed infrastructure, APIs and SDKs that enable developers to implement consumer-grade messaging experiences directly inside their own products.


76% of the world’s population uses a messenger app - that’s 5.8 billion users. SendBird is already the market leader in chat and messaging and we've tripled our revenue year over year. We are expanding our operations globally to continue serving the world’s most innovative companies like Reddit, NBA, Yahoo! Sports, and Delivery Hero.


We are building the most scalable chat infrastructure. We manage over 1.5B messages per month from 100M monthly active users and support over 1M+ concurrent connections per application. We face exciting engineering challenges at scale over a globally distributed infrastructure.

Chat has become the most engaging tool for communicating in marketplaces, on-demand services, and online communities. Real-time chat increases direct communication between key users, leading to more transactions, higher user engagement and retention, and better conversion to key business goals. Building and maintaining a large-scale, globally distributed chat system is a massive engineering effort. That’s why innovative businesses use our technology. By using SendBird’s API, our customers are able to integrate real-time, massively-scaled chat and messaging into any application.

We’re the #1 chat and messaging API and SDK, powering in-app conversation for some of the world’s leading companies.