Senior React Native Engineer (Fantasy Sports)

Sleeper; San Francisco, Northern (CA, KY); On-site; USD 180,000 - 235,000; Full time

Benefits offered by this job

Medical

Dental

PTO

401k

Job summary

Sleeper is hiring a senior mobile developer to shape our fantasy sports app on iOS/Android using React Native and TypeScript. You will focus on scalability, reliability, and performance for millions of daily users, especially around live scoring, drafts, and social features.

You will collaborate with designers and backend teams, build reusable UI components, and stay current with React Native best practices in a fast-paced, ambitious environment in San Francisco.

Qualifications

• 4+ years of mobile app development, React Native focus.
• Ability to ship features end-to-end with performance in mind.
• Strong coding standards and best practices in a large codebase.

Responsibilities

• Collaborate with designers to translate requirements into tech specs.
• Write clean, maintainable React Native/TypeScript code and libraries.
• Troubleshoot performance, sockets, caching, and reliability issues.
• Develop reusable UI components with a scalable architecture.
• Integrate front-end components with backend APIs (REST/GraphQL).

Skills

Mobile development

Performance optimization

Problem solving

Collaborative teamwork

Education

Bachelor's degree in Computer Science or equivalent experience

Tools

React Native

TypeScript

React Query

React Navigation

Reanimated

Job description

About Sleeper:

Sleeper is a rapidly expanding platform for fantasy sports and games, revolutionizing the way sports fans connect and engage. Though once only an NFL fantasy football company, we have continued to expand our offerings over 10+ years of operation with NBA, LCS, and soccer. In Sleeper Picks, our real-money Daily Fantasy Sports (DFS) game, users predict player performance against projections provided by third-party vendors. We are at the forefront of innovation in the sports gaming industry, backed by some of Silicon Valley's top investors.

Role Overview:

You'll be working on our fantasy sports product — season-long leagues, drafts, matchups, live scoring, and the social layer that connects them. It's the core of Sleeper, with traffic that peaks hard on game days and a season calendar that doesn't move. You will play a crucial role in developing our mobile application to ensure scalability, reliability, and quality, impacting millions of dedicated users every day.

Our mobile platform is built on React Native, and has been modernized with TypeScript and many of the leading packages like react-query, react-navigation, and reanimated. We’re looking for an experienced mobile developer who can bring their knowledge and skills to help refine our app; bringing new features, improved quality, and lightning fast performance to our millions of users.

We're hiring at the senior level, but will seriously consider strong mid-level engineers — we care more about what you've shipped and how deeply you understand it than about years on a resume.

Responsibilities:

• Collaborate with designers to understand user requirements and translate them into technical specifications for our fantasy sports product.

• Write clean, maintainable, and efficient code using React Native, TypeScript, and related libraries (React Query, Navigation, Reanimated, etc).

• Troubleshoot and debug complex performance, socket, data caching and other issues.

• Develop reusable UI components and implement a well-structured component hierarchy for the application.

• Integrate front-end components with back-end services using APIs (RESTful or GraphQL).

• Stay up-to-date on the latest advancements in React Native, mobile development best practices, and accessibility guidelines.

Who You Are:

• An active fantasy sports player: you're in leagues each season and have opinions about how the product should work

• 4+ years of mobile application development experience, with React Native as your primary framework

• Desire to take on and own a large scale product with freedom to design and develop a best in class experience

• Proven ability to develop and implement algorithms or systems in a professional setting, with strong coding skills and knowledge of best practices

• Comfortable in fast-paced and ambiguous environments, working inside a large, established codebase

• Hold a degree in Computer Science or have equivalent experience

What We Offer:

• A salary range of $180,000 to $235,000 USD, based on experience, plus benefits including Medical, Dental, PTO, and 401k.

• A small, impactful team environment where you can truly make a difference.

• Support for professional growth with a company backed by leading investors.