Summary: Lead Kotlin Engineer to guide the development of backend systems, mentor the team, and shape architectural decisions for award-winning mobile apps. Highlights: 1. Lead design and development of server-side applications 2. Architect solutions for complex and undefined challenges 3. Collaborate closely with cross-functional teams We are looking for a **Lead Kotlin Engineer** to guide the development of backend systems powering our award\-winning mobile apps. In this role, you will work closely with engineers, product managers, designers, and QA professionals to deliver robust, high\-performing services. Take the lead in solving complex problems, mentor the team, and shape architectural decisions—apply now to help drive our innovative initiatives. **Responsibilities** * Lead the design and development of server\-side applications supporting mobile clients * Refactor, enhance, and remove code where needed to ensure high system quality * Architect solutions for complex and undefined challenges * Oversee integration of backend services with custom legacy systems * Analyze performance and implement optimization strategies * Ensure development and upkeep of comprehensive unit tests * Address bugs and systematically reduce technical debt * Apply asynchronous programming techniques to boost responsiveness * Collaborate closely with cross\-functional teams in product, design, and QA * Manage build tools and maintain continuous integration pipelines * Promote contributions to open source projects and foster knowledge sharing * Drive initiatives and ensure completion of assigned tasks **Requirements** * Bachelor’s degree in Computer Science or equivalent practical experience * 5\+ years of professional Kotlin development experience * Proficiency in building server\-side applications and REST APIs * Hands\-on experience with asynchronous programming and performance optimization * Good command of Gradle and CI practices * Ability to lead and collaborate effectively within a cross\-functional team * Upper\-Intermediate English proficiency level (B2\) **Nice to have** * Familiarity with GraphQL and RAML specifications * Experience with Docker\-based containerization * Expertise in effective unit testing methodologies * Experience maintaining and improving legacy codebases