Summary: Seeking a Senior Server-side Engineer to develop and enhance a mobile application service layer, focusing on performance, clean code, and collaborative problem-solving. Highlights: 1. Develop mobile application service layer for millions of users worldwide 2. Collaborate with multidisciplinary teams on award-winning mobile apps 3. Focus on user experience, elegant code, and innovative solutions We are hiring a **Senior Server\-side Engineer** to develop the Mobile application Service Layer used by millions of people worldwide. The role involves working on the Mobile application Service Layer (Backend for Frontend) utilized by award\-winning mobile apps. You’ll work alongside a multidisciplinary team of engineers, product leaders, designers, and QA specialists. This position demands technical expertise, ingenuity, and a drive to address complex challenges with modern solutions. If contributing ideas, prioritizing user experience, and creating elegant code excite you, we invite you to apply. **Responsibilities** * Build server\-side applications for the mobile service layer * Write clean, efficient, and maintainable code * Refactor legacy code to improve performance and readability * Streamline the codebase by removing outdated code * Develop build tools and maintain continuous integration processes * Address bugs and resolve production issues * Implement asynchronous methods to optimize performance * Analyze and enhance application performance * Create unit tests and uphold code quality standards * Collaborate with product, design, and QA teams * Integrate bespoke backend services into the application * Design innovative solutions for complex challenges * Contribute to open\-source initiatives within the team **Requirements** * Bachelor’s degree in Computer Science or a related field, or equivalent experience * Strong experience with algorithms and data structures, with 3\+ years in server\-side development using Java * Proficiency in Kotlin programming language * Proficiency in REST API design and implementation * Hands\-on experience with Spring Boot framework * Skills in writing unit tests and test\-driven development * Knowledge of asynchronous programming and performance optimization * Background in teamwork and collaboration * Self\-starting mindset supported by problem\-solving expertise * Experience in legacy code refactoring and maintenance * Proficiency in English language, level B2 (Upper\-Intermediate) **Nice to have** * Showcase of Docker containerization experience * Familiarity with Gradle for build automation * Understanding of GraphQL APIs * Background in RAML API modeling