Senior Backend Engineer - Java & Kotlin Microservices

BELVEDERE; Wrocław; On-site; PLN 201,000 - 290,000; Part time

Job summary

BELVEDERE is seeking a Senior Backend Engineer to design, develop, and maintain backend applications using Java and Kotlin within a microservices architecture. You will work on cloud-native solutions, primarily with Azure, and collaborate with cross-functional teams to deliver scalable, secure systems.

Strong ownership and focus on quality are expected. The role involves crafting REST and gRPC APIs, applying Domain-Driven Design, and contributing to CI/CD pipelines for secure, fast software

Qualifications

• 8–10 years of backend software development experience.
• Strong proficiency in Java and/or Kotlin.
• Extensive experience with Spring Boot and microservices architecture.
• Proven experience developing REST and gRPC APIs.
• Hands-on with event-driven architectures (Kafka or RabbitMQ).
• Knowledge of PostgreSQL and relational DB design.
• Experience with Docker and Kubernetes, and cloud-native delivery.
• CI/CD pipelines and Git version control.
• English proficiency for professional communication.

Responsibilities

• Design, develop and maintain backend applications in Java/Kotlin.
• Build microservices using Spring Boot.
• Apply Domain-Driven Design to create scalable systems.
• Develop and integrate REST and gRPC APIs.
• Implement event-driven architectures with Kafka/RabbitMQ.
• Design/optimise PostgreSQL databases.
• Containerise with Docker and deploy to Kubernetes.
• Contribute to CI/CD pipelines and secure software delivery.
• Deploy cloud-native solutions on Azure, AWS, or GCP.

Skills

Java

Kotlin

Spring Boot

Microservices

Docker

Kubernetes

Azure

REST API

gRPC

PostgreSQL

Kafka/RabbitMQ

Spring Security

English

Tools

Docker

Kubernetes

Azure

Job description

Senior Backend Engineer - Java & Kotlin Microservices

Location: Wrocław
Contract Type: 6-Month Contract

Job Type: On-site

• Build scalable microservices using Java, Kotlin and Spring Boot
• Work with cloud-native technologies including Azure, Kubernetes and Docker
• Collaborate with cross-functional teams on high-impact backend solutions
• Apply Domain-Driven Design principles to complex technical challenges

Company Overview

Our client is an established technology organisation delivering robust backend solutions across multiple sectors. They focus on building scalable, cloud-native applications that solve complex business challenges. With a commitment to engineering excellence and modern architectural practices, they create systems that prioritise performance, security and maintainability. Their teams work collaboratively across functions, fostering knowledge sharing and continuous learning to stay ahead of emerging technologies and industry best practices.

They're looking for an experienced Senior Backend Engineer to join their team in Wrocław on a 6-month contract. This is an opportunity to work on microservices-based applications, applying your expertise in Java and Kotlin to deliver high-quality backend solutions that meet critical business objectives.

Position Overview

As a Senior Backend Engineer, you'll design, develop and maintain backend applications using Java and Kotlin within a microservices architecture. You'll work on cloud-native solutions, primarily using Azure, while collaborating with cross-functional teams to deliver scalable, secure and efficient systems. This role requires strong technical ownership, from initial design through to deployment and ongoing support, ensuring long-term stability and performance of the applications you build.

Responsibilities

• Design and develop backend applications using Java and Kotlin
• Build microservices-based solutions leveraging Spring Boot and related frameworks
• Apply Domain-Driven Design principles to create maintainable, scalable systems
• Develop and integrate REST and gRPC APIs
• Implement event-driven architectures using Kafka or RabbitMQ
• Design and optimise database solutions using PostgreSQL
• Containerise applications with Docker and support Kubernetes deployments
• Contribute to CI/CD pipelines for automated, secure software delivery
• Deploy cloud-native solutions on Azure, AWS or Google Cloud Platform
• Incorporate security best practices including OAuth2, SAML and Spring Security
• Analyse technical challenges and deliver high-performance backend solutions
• Participate in design reviews, code reviews and technical discussionsCollaborate with stakeholders and peers across cross-functional teams
• Maintain code repositories through Git version control
• Continuously adopt emerging technologies and engineering practices

Requirements

• 8-10 years of experience in backend software development
• Strong proficiency in Java and/or Kotlin
• Extensive experience with Spring Boot and microservices architecture
• Solid understanding of Domain-Driven Design principles and architectural patterns
• Proven experience developing REST and gRPC APIs
• Hands-on experience with event-driven architectures using Kafka or RabbitMQ
• Strong knowledge of PostgreSQL and relational database design
• Experience with Docker containerisation and Kubernetes orchestration
• Proficiency with CI/CD pipelines and Git version control
• Experience deploying cloud-native solutions on Azure (preferred), AWS or GCP
• Knowledge of security frameworks including OAuth2, SAML and Spring Security
• Ability to analyse complex technical challenges and deliver scalable solutions
• Strong communication skills with professional proficiency in English
• Ownership mindset with focus on quality, stability and maintainability
• Collaborative approach to working with cross-functional teams

Benefits

While specific benefits details are being confirmed, you'll join a technically focused environment where engineering excellence is valued. You'll work alongside experienced professionals who prioritise knowledge sharing, code quality and continuous improvement. The team encourages learning and adopting emerging technologies, supporting your professional development while delivering impactful backend solutions that solve real business challenges.