Fullstack Mobile Developer ( Kotlin)

About the Position

We are looking for a talented and passionate Fullstack Mobile Developer (Kotlin) 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

Requirements

• 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

We Offer

• Salary range: 6,500 - 7,500 EUR/month (netto)
• Location: Warsaw, MZ, Poland / Remote
• Work mode: Remote/Hybrid

About the Company

Integral Solutions is a company specializing in the creation and implementation of IT solutions, with a focus on low-code platforms like OutSystems and technologies supporting integration, automation, and business application development. The company is oriented towards demanding projects, potentially in the banking sector, and works with modern tools such as CI/CD, Microsoft Power Platform, and AI solutions.