We're seeking a Senior Java Developer with strong Kotlin expertise to build and scale the Backend for Frontend (BFF) service layer powering mobile applications used by tens of millions of users worldwide. This is a hybrid role requiring 3 days onsite in Atlanta, GA or Phoenix, AZ. If you thrive on solving complex problems, writing clean code, and building high-performance APIs - we'd love to connect. Req# [redacted] Responsibilities Build & Scale Backend Services: Design, develop, and maintain the server-side API layer consumed by award-winning mobile applications Write High-Quality Code: Deliver clean, well-tested, production-ready Kotlin/Java code with a focus on performance and maintainability Optimize & Refactor: Improve existing systems, modernize legacy code, and drive performance analysis and optimization efforts Integrate Complex Systems: Connect with internal backend services, third-party APIs, and data sources across a distributed architecture Collaborate Cross-Functionally: Work closely with mobile engineers, product managers, designers, and QA to deliver seamless end-to-end experiences Requirements Experience: 5+ years of professional experience in server-side software development with Java; Bachelor's degree in Computer Science or equivalent experience Kotlin: Strong hands-on proficiency in Kotlin for backend development is required API Development: Solid experience building and maintaining RESTful APIs, with familiarity in asynchronous programming and performance optimization Engineering Practices: Strong foundation in unit testing, CI/CD, build tools (Gradle), code reviews, and software development lifecycle best practices Problem Solving: Proven ability to design solutions for open-ended problems, debug complex issues, and work effectively with legacy systems Collaboration & Ownership: Self-starting mindset with excellent communication skills and the ability to thrive in a large, cross-functional team environment Nice to have Experience with GraphQL (GQL) or RAML for API design and documentation Contributions to or experience working with open-source projects Background in building Backend for Frontend (BFF) layers or mobile-facing service architectures