Senior Kotlin Engineer

N-iX; Kraków; On-site; PLN 180,000 - 320,000; Full time

Benefits offered by this job

Flexible working format

Competitive salary

Education reimbursement

Professional development tools

Team events

Job summary

N-iX in Kraków is seeking a Senior Kotlin Engineer to design, build and operate scalable Kotlin microservices on AWS for a leading European fintech client. You will work as a hands-on IC embedded in client squads.

The role emphasizes AI-native delivery, distributed systems, PostgreSQL, Grafana observability, and agile methodologies. It offers flexible remote/hybrid work and opportunities for career growth.

Qualifications

• 5+ years of commercial backend engineering
• Kotlin; scalable microservices on AWS
• AI-native delivery practices 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

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).

Skills

Kotlin

Backend engineering

English communication

Tools

AWS

Grafana

PostgreSQL

EKS

Lambda

SQS

Job description

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

We offer*:

• Flexible working format - remote, office-based or flexible
• A competitive salary and good compensation package
• Personalized career growth
• Professional development tools (mentorship program, tech talks and trainings, centers of excellence, and more)
• Active tech communities with regular knowledge sharing
• Education reimbursement
• Memorable anniversary presents
• Corporate events and team buildings
• Other location-specific benefits
• not applicable for freelancers