Senior React Developer (Remote / Contract)

Jun Group is a technology company building a world where consumers are in control of their data and advertisers can reach them directly. Intelligent advertising that inspires trust is our guiding principle. We’re passionate about making advertising better for everyone through our consent-based approach that empowers the world’s largest publishers, brands, and agencies to achieve their goals with integrity, transparency, and peace-of-mind.

We are looking for a Senior React Developer to join our development team. You will take a leading role in developing and enhancing our core WebView-based ad player, which is a critical component of our mobile AdTech SDKs for iOS and Android. This position is full-time and remote-friendly.

• Take charge of the end-to-end development lifecycle for our React-based player, from technical design and requirement clarification to implementation, testing, and deployment.
• Lead the development and maintenance of our React-based WebView player, ensuring high performance and reliability on mobile devices.
• Build and deploy responsive, mobile-first UIs using React and TypeScript, with a deep understanding of the constraints and capabilities of a mobile WebView environment.
• Collaborate with Product Managers to flesh out features and translate product vision into robust technical solutions.
• Work closely with our iOS (Swift) and Android (Kotlin) SDK developers to design, implement, and debug the JavaScript bridge for seamless communication between the WebView and native mobile code.
• Write comprehensive unit and integration tests to ensure code quality and application stability.
• Actively participate in code reviews, providing and incorporating constructive feedback to maintain high code standards.

• You possess a strong development background with a passion for producing clean, performant, and maintainable applications in TypeScript.
• You have a deep understanding of the web platform and are acutely aware of the differences between a full-fledged browser and a mobile WebView.
• You are a proactive owner, comfortable taking a feature from an idea to a polished, production-ready implementation.
• You have a strong vision of how technology blends with business and take pride in the successful deployment of solutions.
• You enjoy a fun, creative, and diligent work environment and working with a dynamic group of skilled individuals.
• You have good communication skills and a team mentality.

• 5+ years of professional software development experience, with a significant focus on React.
• Expertise in TypeScript and modern JavaScript (ES6+), HTML5, and CSS3.
• Demonstrable experience building complex, responsive UIs with React, specifically for mobile web browsers and WebViews.
• Strong understanding of the nuances of running a web application inside a mobile WebView versus a standard browser (e.g., performance considerations, lifecycle events, security, local storage limitations).
• Proficiency with state management libraries (e.g., Redux, Zustand, or Context API).
• Solid understanding of Git and GitHub for version control.
• Experience writing and executing unit and integration tests (e.g., Jest, React Testing Library).

• Direct experience creating or working with a JavaScript bridge for communication between a WebView and native mobile code (Swift/Kotlin).
• Professional experience in the AdTech industry (e.g., VAST, MRAID, Open Measurement).
• Familiarity with mobile development in Swift (iOS) or Kotlin (Android).
• Experience with video or interactive media players.

• Agile development methodology with a focus on iterative development and continuous improvement.
• Emphasis on rigorous code inspection and quality assurance.
• Collaborative environment with experienced team members.
• Strong commitment to unit and integration testing.

We’re open to allowing the right person to learn our industry on the job. We welcome diversity and non-traditional paths into all of our roles. We believe in hiring the right person as opposed to the right combination of keywords.

Communications regarding your application will only come from @jungroup.com or @hyprmx.com email addresses.