Senior Backend Engineer — Java 21+, Spring, Kubernetes

SOLID.Jobs; Kraków; On-site; PLN 280,000 - 360,000; Full time

Job summary

SOLID.Jobs is seeking a Senior Backend Engineer to design and implement scalable services and microservices in a modern network management platform. You will influence architecture, drive performance, and deliver robust distributed systems in a distributed engineering team.

You will work with Java 21+, Spring Boot, Kubernetes, Azure, Kafka, and PostgreSQL, focusing on reliability, code quality, and efficient operation in an international environment.

Qualifications

• Strong commercial experience with Java, preferably Java 21+
• Very good knowledge of Spring / Spring Boot
• Strong understanding of OOP, clean code, and software engineering principles
• Experience designing and developing microservices and distributed systems
• Experience with Kubernetes
• Experience with cloud platforms, preferably Microsoft Azure
• Hands‑on experience with messaging technologies such as Kafka and/or Azure Event Hubs
• Strong knowledge of PostgreSQL, including database design and optimisation
• Experience with performance tuning and optimisation of backend services
• Good knowledge of Git and GitHub
• Practical knowledge of Linux and scripting/automation
• Understanding of networking fundamentals
• Experience using generative AI tools such as GitHub Copilot or Google Gemini in software development
• Very good troubleshooting and analytical skills
• English allowing effective communication in an international engineering environment

Responsibilities

• Design, develop, and maintain backend services and microservices using Java 21+ and Spring
• Contribute to architecture and technical design decisions for distributed systems
• Build and orchestrate microservices running in Kubernetes and cloud environments
• Develop event-driven solutions using Kafka and Azure Event Hubs
• Design, manage, and optimise PostgreSQL databases
• Improve application performance, scalability, reliability, and resource utilisation
• Troubleshoot complex backend, networking, performance, and orchestration issues
• Work with Azure, Kubernetes, Linux, Git, and GitHub
• Use GitHub Copilot and Google Gemini as part of the daily software development workflow
• Maintain high standards of clean code, testing, and software engineering practices
• Participate in technical discussions, code reviews, and architectural improvements
• Collaborate with other engineers in an Agile environment

Skills

Java

Java 21+

OOP

Clean code

Software engineering principles

Distributed systems

Troubleshooting

English communication

Agile

Tools

Java 21+

Spring

Spring Boot

Kubernetes

Azure

Kafka

Azure Event Hubs

PostgreSQL

Git

GitHub

Linux

GitHub Copilot

Google Gemini

Job description

SOLID.Jobs is seeking a Senior Backend Engineer to design and implement scalable services and microservices in a modern network management platform. You will influence architecture, drive performance, and deliver robust distributed systems in a distributed engineering team.

You will work with Java 21+, Spring Boot, Kubernetes, Azure, Kafka, and PostgreSQL, focusing on reliability, code quality, and efficient operation in an international environment.