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.