Senior Full-Stack Developer (NX13)

🚀 Hello, guys! We’re looking for a Senior Full-Stack Developer (React.js + .NET) to join an innovative R&D team in Warsaw for full-time employment.
You’ll be part of a fast-growing Sport-tech product company that’s using AI to help leading global sports brands create and deliver real-time video content. 

If you’re interested in building high-performance tools that reach millions of users, this could be a great opportunity for you.

📍Type of work: hybrid format (2-3 days/week in the office - Warsaw, Poland)

⭐English: Upper-Intermediate.

🕐Engagement: Full-time, long-term cooperation. 

📌Responsibilities:

• Build and maintain a high-performance, browser-based video editing platform used by global media teams;
• Develop client-side features using React.js + TypeScript and server-side logic using C# / .NET Core;
• Design and implement modular, reusable components for timeline management, video preview, trimming tools, overlay controls, and more;
• Develop and maintain scalable backend APIs for video rendering, encoding, and delivery;
• Collaborate closely with Product, Design, QA, and Engineering teams in daily standups, planning sessions, and code reviews;
• Ensure robust testing, clean documentation, and smooth CI/CD pipelines to support reliable deployments;
• Monitor system behavior in production, identify issues across the stack, and deliver timely fixes;

• Share knowledge with peers, contribute to internal engineering initiatives, and stay up to date with industry trends in video tech. 

   

📍Requirements:

• 4+ years of hands-on experience building production-grade web applications (Full-stack);
• Strong knowledge of React.js, TypeScript, JavaScript, modern HTML/CSS;
• Solid experience with C#, .NET Core, asynchronous programming, and RESTful API design;
• Familiarity with SQL and basic knowledge of NoSQL tools like Redis;
• Practical understanding of cloud infrastructure (preferably Azure, AWS, GCP) and CI/CD tools like GitHub Actions or Azure DevOps;
• Ability to debug complex systems and write maintainable, testable code;
• English: Upper-Intermediate;
• Strong communication skills and comfort working with cross-functional teams;

• Self-motivated with a focus on delivering great user experiences.

   

Will be a plus:

• Experience working with multimedia/video frameworks or streaming protocols (HLS, MPEG-DASH);

• Familiarity with event-driven architectures and messaging systems (e.g., Kafka, Service Bus);

   

🎁What we offer:

• A Decent salary range;
• Medical insurance;
• Paid vacation and sick leaves;
• MultiSport card;
• Top equipment kit, co-workings;
• Hybrid set of works (Office location: Warsaw);
• Collaborative and innovative work environment;
• Career growth and development opportunities;
• A chance to work with giants of the sports industry.