Senior Software Engineer (Java, GCP)

Capgemini; Poland; Hybrid; PLN 240,000 - 360,000; Full time

Benefits offered by this job

Hybrid work model

Extensive training tracks

Private medical care

Life insurance

Job summary

Capgemini Poland is seeking an experienced Senior Java backend developer to design and build robust services using Java and Spring, with a strong focus on microservices, REST APIs and performance. You will collaborate with DevOps on cloud infrastructure (GCP, Terraform), write unit and integration tests (JUnit, Mockito), and contribute to architecture and code reviews; you’ll enjoy a hybrid work model.

The role demands 5+ years of Java experience, memory management and concurrency skills;

Qualifications

• 5+ years of Java development experience.
• Strong knowledge of Java memory model and GC.
• Experience with REST APIs and microservices.
• Experience with cloud and DevOps practices.

Responsibilities

• Designing and developing backend systems using Java and Spring ecosystem.
• Building and maintaining microservices-based architectures.
• Writing high-quality, maintainable code with focus on performance and scalability.
• Implementing unit and integration tests (JUnit, Mockito).
• Analyzing and resolving performance issues (memory leaks, GC behavior).
• Applying modern Java features and best practices in daily development.
• Collaborating with DevOps teams on cloud and infrastructure (GCP, Terraform).
• Participating in code reviews, technical discussions, and architecture design.

Skills

Java development

Spring Boot

Microservices

REST APIs

Memory management

Multithreading

JUnit/Mockito

GCP cloud

Terraform basics

Agile/Scrum

Code reviews

Tools

Docker

Kubernetes

Jenkins

GitLab CI

Terraform

Kafka

ActiveMQ

JUnit

Mockito

GCP

Job description

Choosing Capgemini means choosing a company where you will be empowered to shape your career in the way you’d like, where you’ll be supported and inspired by a collaborative community of colleagues around the world, and where you’ll be able to reimagine what’s possible. Join us and help the world’s leading organizations unlock the value of technology and build a more sustainable, more inclusive world.

Your Role

On this role, you will be responsible for designing and developing backend systems using Java and the Spring ecosystem, with a strong focus on microservices architecture. You will ensure high code quality, performance, and scalability while implementing automated tests and resolving performance-related issues. You will actively collaborate with DevOps teams on cloud infrastructure and contribute to code reviews, technical discussions, and architecture design.

Your Tasks

• Designing and developing backend systems using Java and Spring ecosystem
• Building and maintaining microservices-based architectures
• Writing high-quality, maintainable code with strong focus on performance and scalability
• Implementing unit and integration tests (JUnit, Mockito)
• Analyzing and resolving performance issues (e.g., memory leaks, GC behavior)
• Applying modern Java features and best practices in daily development
• Collaborating with DevOps teams on cloud and infrastructure (GCP, Terraform)
• Participating in code reviews, technical discussions, and architecture design

Your Profile

• 5+ years experience in Java development
• Strong knowledge of core Java (collections, access modifiers, exception handling)
• Understanding of Java memory model, memory structure, and Garbage Collection
• Engineering experience and a systems-thinking mindset
• Ability to identify and resolve memory leaks
• Solid knowledge of concurrency (synchronized, volatile, atomic types)
• Experience with Future / Completable Future and multithreading concepts
• Familiarity with modern Java features (records, sealed classes, default methods, virtual threads – at least theoretical)
• Hands‑on experience with Spring Boot and Spring Data
• Experience in designing and implementing REST APIs and microservices
• Practical experience with unit and integration testing (JUnit, Mockito)
• Understanding of microservice architecture principles
• Exposure to GCP
• Nice To Have Docker, Kubernetes (cloud-native approach)
• Messaging systems (Kafka, ActiveMQ)
• CI/CD tools (Jenkins, GitLab CI)
• Basic knowledge of Terraform / Infrastructure as Code
• Experience working in Agile (Scrum/Kanban)
• Experience in distributed systems and observability tools
• Experience working with high-load systems

What You'll love about working here

Enjoy hybrid working model that fits your life - after completing onboarding, connect work from a modern office with ergonomic work from home, thanks to home office package (including laptop, monitor, and chair). Access to over 70 training tracks with certification opportunities (e.g., GenAI, Architects, Google) on our NEXT platform. Dive into a world of knowledge with free access to Education First languages platform, Pluralsight, TED Talks, Coursera and Udemy Business materials and trainings. Practical benefits: private medical care with Medicover with additional packages (e.g., dental, senior care, oncology) available on preferential terms, life insurance and 40+ options on our NAIS benefit platform, including Netflix, Spotify or Medicover Sport.

Get To Know Us

Capgemini is committed to diversity and inclusion, ensuring fairness in all employment practices. We evaluate individuals based on qualifications and performance, not personal characteristics, striving to create a workplace where everyone can succeed and feel valued. Do you want to get to know us better? Check our Instagram — @capgeminipl or visit our Facebook profile — Capgemini Polska. You can also find us on YouTube.

About Capgemini

Capgemini is an AI-powered global business and technology transformation partner, delivering tangible business value. We imagine the future of organizations and make it real with AI, technology and people. With our strong heritage of nearly 60 years, we are a responsible and diverse group of over 420,000 team members in more than 50 countries. We deliver end‑to‑end services and solutions with our deep industry expertise and strong partner ecosystem, leveraging our capabilities across strategy, technology, design, engineering and business operations. The Group reported 2025 global revenues of €22.5billion.