Senior Full Stack Developer (Fintech)

Location: Warsaw, Poland — hybrid, with remote and in-person work

Company

A fintech business builds point-of-sale financing and consumer credit products for everyday service businesses, deployed across thousands of service locations and managed through a no-fee mobile credit card. The hiring partner is a globally operating staffing company.

What you will do

• Develop and maintain the customer-facing native mobile application.
• Own end-to-end development of new platform features from concept through deployment.
• Collaborate with backend engineers to integrate APIs and deliver a seamless, high-performance user experience.
• Write clean, efficient, maintainable code in line with engineering standards.
• Contribute to a collaborative environment, share expertise, and mentor other team members.

Requirements

• 5+ years of frontend or mobile development experience.
• Strong production experience with React.
• Deep knowledge of JavaScript, TypeScript, and CSS.
• Experience publishing and maintaining applications in Google Play and the App Store.
• Strong ownership mindset; proactive, resourceful, self-motivated, and able to work independently in a fast-paced environment.
• B.Sc. in Computer Science or equivalent.
• Fluent English required for daily collaboration with the Israel team.

Nice to have

• 2–3 years of backend development experience with Java or Kotlin.
• Strong React Native experience, including app lifecycle management and deployment to stores.
• Experience with end-to-end testing frameworks such as Playwright.
• Knowledge of WebSockets.
• Fintech experience, especially in payment processing or financial services.
• Experience with AI development tools such as Cursor and Claude Code.

Culture & Benefits

• Hybrid work arrangement combining remote and in-person work in Warsaw.
• Collaborative environment with opportunities to share expertise and mentor colleagues.
• Daily collaboration with an Israel-based team.
• Benefits are provided by the staffing company; further details are available from the hiring contact.