Middle Java Software Engineer

Ciklum
is looking for a
Middle Java Software Engineer
to join our team in Poland.

We are a custom product engineering company that supports both multinational organizations and scaling startups to solve their most complex business challenges. With a global team of over 4,000 highly skilled developers, consultants, analysts and product owners, we engineer technology that redefines industries and shapes the way people live.

About the role:

Seeking a strong Middle Java Software Engineer who brings deep expertise in backend development using Java 8+, Spring Boot, and microservices architecture. This role requires hands-on experience with Java Streams, RESTful API design, and secure communication practices including TLS/mTLS. You will be responsible for building scalable, maintainable, and production-ready applications and services, while mentoring junior developers and advocating for best engineering practices.

Responsibilities:

• Design, develop, and maintain backend services using Java (Java 8+) and Spring Boot
• Build and expose RESTful APIs (e.g., weather API) following REST standards
• Apply microservices principles to architect and decouple complex systems
• Implement circuit breakers using tools such as Resilience4j to ensure resilience in distributed systems
• Handle exceptions effectively using Spring's @ControllerAdvice, and configure fallback mechanisms
• Use Java Streams for complex data transformations:
• Implement operations like flatMap, sorted, collect, and groupingBy with custom collectors
• Solve code problems such as counting word occurrences or flattening nested lists
• Configure Servlet-based error handlers for low-level HTTP exception handling
• Ensure secure communication using TLS/mTLS, and manage trust stores/key stores configurations for encrypted data exchange
• Participate in code reviews, provide constructive feedback, and ensure quality, security, and performance of deliverables
• Collaborate with cross-functional teams to deliver production-ready features and troubleshoot production issues
• Proactively address technical debts, enforce best practices, and write clean, testable code
• Mentor junior developers and support their technical growth

Requirements:

• Strong proficiency in Java 8+, including hands-on experience with Streams API and lambda expressions
• Solid understanding of Spring Boot internals and REST API development
• Deep experience with microservices architecture, including service registration/discovery and fault tolerance patterns
• Familiarity with Resilience4j or similar libraries (Hystrix, etc.) for resilience
• Strong grasp of exception handling, particularly using @ControllerAdvice, @ExceptionHandler
• Experience using Servlet error handling mechanisms
• Practical experience with Java Stream operations for real-time data processing
• Knowledge of TLS, mTLS, and configuring keystores/truststores for secure data communication
• Understanding of CI/CD, logging, monitoring, and deploying Java-based services in production
• Good knowledge of unit testing, integration testing frameworks (e.g., JUnit, Mockito)
• Strong debugging and problem-solving skills

What`s in it for you?

• Strong community: Work alongside top professionals in a friendly, open-door environment
• Growth focus: Take on large-scale projects with a global impact and expand your expertise
• Tailored learning: Boost your skills with internal events (meetups, conferences, workshops), Udemy access, language courses, and company-paid certifications
• Endless opportunities: Explore diverse domains through internal mobility, finding the best fit to gain hands-on experience with cutting-edge technologies
• Flexibility: Enjoy flexibility – full remote working possibilities
• Care: We've got you covered with company-paid medical insurance, mental health support, and financial & legal consultations

About us:

At Ciklum, we are always exploring innovations, empowering each other to achieve more, and engineering solutions that matter. With us, you'll work with cutting-edge technologies, contribute to impactful projects, and be part of a One Team culture that values collaboration and progress.

With delivery centers in Wrocław and Gdańsk, our 300+ professionals in Poland drive forward-thinking solutions for global clients. Join a community where collaboration sparks innovation—and your impact reaches millions.

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Explore, empower, engineer with Ciklum

Interested already? We would love to get to know you Submit your application. We can't wait to see you at Ciklum.