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Fullstack Mobile Developer ( Kotlin)

Summary

Build and maintain a large-scale fintech platform’s mobile apps and backend services using Kotlin Multiplatform, Spring Boot, and cloud-native tools to process real-time payments and financial integrations.

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

About the company/project:

We are looking for a talented and passionate Fullstack Mobile Developer to join our team and contribute to the development of innovative, customer-facing digital products in a fast-paced and technology-driven environment.

As part of the team, you will work on a large-scale fintech platform supporting real-time digital payments, money transfers, account balance management, merchant payments, and financial service integrations.

The solution serves a large user base and processes high volumes of transactions through a combination of mobile applications, distributed backend services, APIs, and secure transaction processing systems.

This is an opportunity to work on a business-critical product where scalability, reliability, security, and user experience are at the core of every engineering decision.

The platform operates in a highly demanding environment, requiring modern software architecture, seamless integration between mobile and backend systems, and the ability to deliver performant solutions at scale.

Working on such a product offers exposure to complex technical challenges, high-traffic systems, and the unique demands of building secure financial services used by millions of end users.

Responsibilities:

  • Design, build, and maintain complex mobile systems at scale, integrating advanced technologies

  • Develop advanced fintech products with end-to-end ownership and operational responsibility

  • Lead and deliver fullstack solutions from concept to production

  • Collaborate closely with cross-functional teams to continuously improve the product

  • Design and implement scalable and robust software architectures

  • Ensure high code quality, performance, and system reliability

You are an ideal candidate if you have:

  • 5+ years of software development experience

  • Strong Fullstack experience with a significant focus on Mobile

  • Hands-on experience with Kotlin Multiplatform (KMP)

  • Deep understanding of client-side architecture and Clean Architecture

  • Experience with Spring Framework and Spring Boot

  • Strong understanding of distributed systems and microservices architecture

  • Experience working with Kafka, REST APIs, and event-driven architectures

  • Experience with Docker, Kubernetes, and CI/CD processes

  • Familiarity with AWS – an advantage

Nice to have:

  • 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

What we offer:

See also