Fullstack Mobile Developer ( Kotlin)

Job title: Fullstack Mobile Developer (Kotlin Multiplatform)
Location: Poland / Remote/ Warsaw
Work mode: Remote/ Hybrid
Type of cooperation: B2B contract 
Salary range: B2B  6500 - 7500 Euro/month- netto

You will join a team building next-generation digital financial products used by customers at scale. You will work across the mobile app, shared mobile logic, backend services and production systems.
We are moving towards a new development model: smaller teams with stronger ownership, more code reuse between platforms, and practical use of AI development tools. You do not need to know everything on day one, but you should be curious, hands-on and able to learn quickly.

• Build and improve mobile features used by real customers.
• Develop shared business logic for mobile platforms, mainly using Kotlin Multiplatform (KMP)
• Build backend services and APIs using Java/Kotlin and Spring Boot.
• Work with cloud services, CI/CD pipelines, monitoring and production support.
• Improve performance, reliability, security and user experience.
• Use AI coding tools to help with development, testing, documentation and troubleshooting.
• Work closely with product, design, architecture, security and platform teams.
• Help define good engineering practices and mentor other developers.

We are looking for a strong engineer, not just a person who knows one framework. KMP experience is a strong advantage, but it is not the only path into this role.

• Strong experience in mobile application development.
• Deep understanding of iOS&Android Architecture Components.
• Strong Kotlin skills and good understanding of modern mobile architecture.
• Experience building production-grade apps with good quality, performance and maintainability.
• Backend development experience with Java and Spring Boot.
• Understanding of APIs, microservices and event-driven systems.
• Experience with CI/CD, automated testing and production systems.
• Ability to take ownership of a feature from design to production.
• Good communication skills and ability to work with multiple teams.

Cross-platform experience
Our strategic direction is Kotlin Multiplatform, because it lets us reuse business logic while still keeping native-quality mobile experiences.

However, we also welcome candidates with strong experience in other cross-platform technologies.

• Strong communication and teamwork skills
• Ability to thrive in a fast-paced, dynamic environment
• Proactive, “Can-Do” attitude
• Strong problem-solving and system-thinking abilities