Fullstack Mobile Developer
Senior Full-Stack Mobile Developer
Salary: $40/hour on B2B
100% Remote
We're looking for a Senior Full Stack Mobile Developer for an international technology group delivering large-scale digital solutions to the financial sector. Their engineering organization is moving toward smaller teams with broader ownership, more code sharing across mobile platforms, and pragmatic use of AI in everyday development. You'd join the group behind customer-facing banking products - working across the app itself, the logic shared between mobile platforms, and the services and infrastructure that power it.
Working stack: Kotlin, Kotlin Multiplatform, Java, Spring Boot, AWS, Kafka.
A senior individual contributor role with real end-to-end scope. You'll carry features from technical design through release and production support, and help shape how mobile architecture and shared code evolve across the team.
Requirements:
Solid track record of shipping production mobile applications, with a deep grasp of Android and iOS architecture components
Advanced Kotlin skills and command of modern mobile architecture patterns
Hands-on backend development with Java 7+ (or Kotlin) and Spring Boot, building REST APIs
Familiarity with microservices, distributed systems, and event-driven design
Practical experience with CI/CD, automated testing, and operating production systems
Comfort owning a feature end-to-end - from design through deployment and beyond
Strong communication skills and experience collaborating across product, design, security, and platform teams
Day-to-day use of AI coding assistants (Copilot, Cursor, Claude Code, or similar), paired with critical review of generated output for quality, security, and performance
Fluent written and spoken English
Nice to Have:
Kotlin Multiplatform in production - a strong advantage
Flutter or React Native background, with willingness to pick up KMP
Kafka or comparable event-streaming technologies
AWS or another major cloud platform
Fintech, banking, payments, or other regulated-industry experience
Apple Pay, Google Pay, or wallet/payment integrations
Modular mobile architecture or shared SDKs/libraries
Observability, performance profiling, and production incident analysis
Experience working with specs, examples, and tests as the driver of implementation
Key Responsibilities:
Design, build, and refine mobile features used by a large customer base
Develop shared cross-platform business logic, primarily with Kotlin Multiplatform
Build and maintain backend services and APIs in Java/Kotlin with Spring Boot
Contribute to cloud infrastructure, delivery pipelines, monitoring, and production support
Apply AI tooling across the development lifecycle - code, tests, documentation, debugging - while holding a high bar for quality, security, and maintainability
Collaborate closely with product, design, architecture, security, and platform teams
Mentor other engineers and help define team-wide engineering practices
Continuously improve performance, reliability, security, and user experience