Senior Kotlin Engineer

Location: European Union

Department: Delivery Unit (R. Voroniak)

N-iX is looking for Senior Kotlin Engineer - to join the team

Our client is a fast-growing European fintech company in the business spend management space. Products include smart corporate cards, software for business analytics optimisation, and automated invoice management. Operates primarily in Europe, serving SME and mid-sized business customers in a regulated environment (GDPR). We're looking for a Senior Back-End Engineer to design, build and operate scalable Kotlin microservices on AWS, increasing delivery throughput without compromising quality

Responsibilities:

• Design, build and operate scalable Kotlin microservices on AWS.
• Apply AI-native delivery practices across the CDLC to increase delivery throughput without compromising quality.
• Work with distributed systems, relational databases (e.g. PostgreSQL), and observability tooling (e.g. Grafana) in production.
• Multiply the output and quality of the squad you join, and share patterns/practice beyond your immediate team so adoption compounds across the organisation.
• Embed directly into a client squad as a hands-on Individual Contributor (not a coaching/managerial role).

Requirements:

• 5+ years of commercial backend engineering
• Kotlin; scalable microservices on AWS.
• AI-native delivery practices applied across the CDLC
• Production experience with distributed systems
• Relational databases, e.g. PostgreSQL
• Observability tooling, e.g. Grafana
• Excellent English communication skills
• Experience working in Agile / Scrum / Kanban

Nice-to-Have:

• Specific AWS services (EKS, Lambda, SQS) or Prometheus. The RFP names AWS and Grafana only (Grafana as an example of observability tooling) — these additional specifics are common adjacent tools, not stated requirements