Senior ReactJS Engineer

Fliff unpacks sports gaming into social, free-to-play games for all types of sports fans. We've built a social sports gaming experience that allows users to compete for leaderboard positioning, to achieve badges and build their status within the game.

We are pioneering play-for-fun sports gaming, with our flagship social sportsbook experience that includes sweepstakes promotions and loyalty rewards. We provide sports fans with fun, engaging, and free-to-play alternatives to real money gaming.

Who We Are Looking For

If you are passionate about building scalable and engaging web applications, we want you on our team! Fliff is seeking a talented Sr. ReactJS Engineer to join our growing Social Sportsbook team. You’ll be part of a cross-functional group responsible for the full software development life cycle, focusing on delivering top-tier web experiences for both mobile and desktop platforms. The Sportsbook Reliability is a dynamic team that brings together skilled engineers and product managers who collaborate closely to build, release, and support live apps that our users love. We operate in Eastern European Time (EET/EEST). 

The Role:

• Develop and maintain responsive web applications using ReactJS, ensuring a seamless experience across devices.
• Collaborate with backend, DevOps, and designers to implement new features and optimize the live product.
• Support the live platform by identifying and resolving real-time performance issues.
• Design scalable solutions with attention to responsive UIs using pure CSS/SCSS without relying on external frameworks.
• Mentor junior engineers and provide code reviews to maintain high standards.
• Leverage Redux, React-Redux bindings, and middleware (Thunk/Saga) for state management.
• Implement RESTful APIs using axios and fetch, with optional GraphQL integration via Apollo client.

Experience Required:

• 5+ years of experience building modern web applications, with strong expertise in ReactJS and React Hooks (useState, useEffect, custom hooks).
• Advanced TypeScript skills, including utility types (Partial, Pick), generics, and infer keyword usage.
• Solid understanding of Redux mechanics, React-Redux bindings, and internal hooks.
• Strong CSS/SCSS knowledge, with the ability to build reusable, responsive UIs without external libraries (e.g., Material UI, Tailwind).
• Knowledge of WebSockets (native and socket.io) to handle real-time data.
• Experience with RESTful APIs, axios, and fetch, with optional GraphQL and Apollo Client experience.
• Familiarity with React Router for dynamic imports, lazy loading, and code splitting.
• Comfortable with UI tools like Figma, along with React DevTools, Chrome debugger, and testing tools such as Jest and Cypress.
• Adaptability and problem-solving skills to handle real-time challenges and evolving project requirements.
• Strong communication skills and a collaborative mindset to work effectively with cross-functional teams.

Benefits

• Competitive compensation package.
• Opportunity for professional development in a dynamic, fast-growing company.
• Supportive, collaborative, and knowledge-driven work environment.
• Engaging and challenging role with the freedom to innovate and build exciting solutions in the sports gaming industry.

Why Join Us?

At Fliff, you’ll have the opportunity to shape the future of social sports betting by working on exciting, fast-paced projects and supporting a live app. We value creativity, collaboration, and problem-solving, and we’re looking for someone ready to take ownership and make an impact.

We are a multinational company with our headquarters based in Philadelphia, and offices in New York, Austin, and Sofia, Bulgaria. Wherever we are in the world, we pride ourselves on being a close-knit, focused team that is welcoming and friendly, and the work that we do is always interesting and rewarding. Wherever we are in the world, we pride ourselves on being a close-knit, focused team that is:

Welcoming and Friendly

We want to reflect the diversity of the cities we serve. By creating an inclusive culture where everyone can thrive, we’ll make Fliff better for employees and customers alike.

Lively and Creative

We respect and value each other’s ideas, experience and expertise. There is no such thing as a bad idea; only ideas that are executed and ideas that are discarded after consideration.

Stimulating and Rewarding

We know bright minds love a challenge, and we understand your desire to see your hard work pay off. We’ll make sure your daily tasks align with your career ambitions as we grow together.