Senior Data Backend Engineer

N-iX is looking for a Senior Data Backend Engineer (Kotlin) to join a new engagement with a leading European fintech company. This is an exciting opportunity to become part of a modern engineering organization that is redefining how businesses manage corporate spending through innovative financial technology solutions.

The company is building an AI-native engineering environment where developers leverage cutting-edge AI tools throughout the software development lifecycle. You'll work within cross-functional product squads, contributing to both existing platforms and new product initiatives while helping shape scalable, data-driven backend services.

Responsibilities:

• Design and develop scalable backend services using Kotlin.
• Build and own clean API layers serving both internal and customer-facing products.
• Work at the intersection of backend engineering and data platforms, integrating analytical data into product experiences.
• Develop solutions leveraging BigQuery and OLAP serving layers.
• Collaborate closely with cross-functional engineering teams in an agile environment.
• Apply AI-assisted development practices using modern engineering tools.
• Contribute to high-quality, maintainable, and scalable software architecture.

Requirements:

• Strong commercial experience with Kotlin.
• Hands-on experience with BigQuery in production environments.
• Experience working with OLAP serving layers and analytical query systems.
• Solid background in backend architecture and API design.
• Experience building production-grade distributed systems.
• Strong understanding of modern software engineering best practices.
• Professional level of English.
• Currently based in the European Union.

Nice to have:

• Java experience.
• PostgreSQL.
• AWS and/or GCP.
• Experience with REST and/or gRPC APIs.
• Familiarity with AI-assisted development tools such as GitHub Copilot or Claude Code.