Senior Backend Engineer (Kotlin/Spring Boot)

Nexer Czech Republic is a division within DANIR AB

• an IT consulting and R&D company. We have the opportunity to work with world‑renowned brands from Scandinavia, the USA, the UK, and Western Europe. Our goal is to grow strong but rather in competencies than in numbers. If you like what we do, see our offer — maybe it is you we will have the pleasure to meet! :)

About the Role

We are looking for a Senior Backend Developer to join a long‑term project for a major international company. You will work on modern application development using Kotlin, Spring Boot, and Kafka, contributing to a microservices‑based ecosystem running in the cloud. The role involves building reliable, scalable services, ensuring clean technical design, and collaborating closely with cross‑functional engineering teams.

What You Will Do

• Develop backend services in Kotlin using Spring Boot
• Design and build applications in a microservices environment
• Work with Kafka for asynchronous communication
• Collaborate on system design and architecture discussions
• Implement REST APIs and integrate with internal services
• Work in a cloud-native environment using AWS and Kubernetes
• Write unit, integration, and end‑to‑end tests in Kotlin ecosystem
• Use Git for version control and follow clean coding standards
• Ensure responsible and effective adoption of AI tools where relevant
• Work closely with other developers, architects, and product teams
• Participate in code reviews, technical discussions, and knowledge sharing

Who You Are

• At least 5 years of experience as a Backend Developer
• Excellent knowledge of Kotlin, Spring Boot, and SQL (PostgreSQL preferred)
• Hands‑on experience with Apache Kafka
• Strong understanding of microservices design and asynchronous communication
• Comfortable working in a cloud environment (AWS preferred)
• Experience working with Kubernetes, Git, and REST APIs
• Skilled in writing high‑quality automated tests
• Strong communication skills, proactive teamwork, and ownership mindset
• Passionate about clean, maintainable, easy‑to‑read code
• Knowledge of responsible usage of AI models to improve efficiency
• Fluent English (C1), both spoken and written
• Based in Czechia, Slovakia or Poland to support collaboration and occasional team meetups

Must Have

• Kotlin
• SQL (PostgreSQL preferred)
• Spring Boot
• Kafka

Good to Have

• Kubernetes
• AWS

Assignment Details

• Workload: Full time
• Location: Czechia, Slovakia, Hungary (remote)
• Contract type: B2B
• Client: A leading global company (name not disclosed)

Why Nexer

At Nexer, competence and curiosity come first. We collaborate with leading global brands and offer meaningful, transformative projects where your expertise truly matters. You’ll join a culture that encourages innovation, ownership, and continuous professional growth.

Apply

If this sounds like your next challenge, we would be delighted to meet you. Apply today — your promising future might start here.