Senior Software Engineer (Backend)

Join Sleeper, a leading platform in fantasy sports and daily fantasy sports (DFS). As a Senior Software Engineer (Backend), you will design and build core backend systems, optimize system performance, and collaborate cross-functionally to deliver innovative features. You will own significant parts of the backend stack and help raise the bar for performance, scalability, and reliability. Enjoy benefits such as unlimited vacations, 401k and health insurance, team outings, and company-sponsored fantasy leagues.

• Design and build core backend systems that power Sleeper's games and real-time user experiences, ensuring scalability and reliability.
• Own backend initiatives from concept to deployment, ensuring clean interfaces, well-documented services, and resilient infrastructure.
• Collaborate cross-functionally with product, design, and frontend teams to deliver features that users love, contributing to code reviews and backend engineering best practices.
• Strong product mindset—you care about the why, not just the how, and you build with users in mind
• Comfortable designing and maintaining RESTful and/or graphql APIs, data models, and internal tooling
• Bonus: Proficiency in Elixir
• Proven ability to build and scale distributed systems that serve millions of users in real-time or gaming environments
• Solid knowledge of databases (both SQL and NoSQL), caching strategies, and message queues (e.g., Kafka, RabbitMQ, Pub/Sub)
• Bonus: Passion for sports, gaming, or building multiplayer or real-time systems
• Excellent communication and collaboration skills
• Strong proficiency in one or more backend languages (e.g., Go, Python, Node.js, Java), and an understanding of trade-offs between them
• 5+ years of backend software engineering experience
• Cloud experience (AWS, GCP, or similar), with familiarity with containers (Docker) and orchestration (Kubernetes a plus)