The Role We're looking for a Backend Developer to join our team and contribute to building scalable APIs and services that power our language learning experience. You'll work on features ranging from exercise generation systems to user progression tracking, content management, and third-party integrations. What You'll Do Design and develop RESTful APIs for our mobile and web applications Build and maintain modular content systems with configurable schemas and validation rules Work with complex MongoDB schemas Develop content processing pipelines including lyric analysis, translations, and synchronization features Implement content management workflows with approval systems for creators Optimize database queries and indexes for performance at scale Integrate with third-party services (music APIs, payment providers, AI translation models) Collaborate with frontend and mobile developers to deliver seamless user experiences Requirements 3+ years of experience in backend development Strong proficiency with Node.js Extensive experience with MongoDB (aggregations, indexing, schema design) Experience building and documenting RESTful APIs Understanding of authentication and authorization patterns Familiarity with queue systems and background job processing Good understanding of data modeling for complex relationships Experience with Git and collaborative development workflows