Senior Backend Engineer - Payments & Fraud

About the role

Papaya, a fast-growing mobile gaming company, is hiring a Senior Backend Engineer for its Payments & Fraud team in Warsaw. The team builds core products such as registration, account management, payments, restrictions, tournaments and matchmaking, and handles payments and fraud prevention across the platform. The role suits someone who wants to design and develop high-scale, resilient backend services in a fast-paced, technical environment.

Key responsibilities

• Develop and maintain a high-scale backend platform serving millions of users.
• Design and implement end-to-end solutions that reduce time-to-market and improve system efficiency.
• Write high-quality, performant and maintainable code following industry best practices.
• Experiment with new technologies, tools and third-party frameworks.
• Mentor new team members and contribute to a culture of engineering excellence.

Required profile

• 6+ years of experience in server-side development and architecture.
• Hands-on experience in cloud-based architectures and scalable backend systems.
• Experience or strong interest in agentic coding and AI-assisted development tools.
• Passion for learning and adopting new technologies.
• A can-do approach, problem-solving mindset and ability to work in a fast-paced environment.

Required skills

• AWS and Kubernetes
• Node.js or another major backend language
• TypeScript
• Redis and MySQL

What we offer

• Hybrid work model with a growing Warsaw office.
• Competitive compensation tailored to the Polish market via a B2B service agreement.
• Comfortable office in central Warsaw.
• Luxmed medical services.
• Monthly Pyszne.pl voucher and multisport card.
• Monthly happy hours, snacks and breakfasts.