Senior Backend Java Developer

🏢 Summary: Full-time Senior Java Developer role focused on designing and maintaining high-performance, secure backend systems in a cloud-native environment. The position involves leading technical design, developing scalable applications with Java 17+ and Spring Boot, and supporting CI/CD and Kubernetes-based deployments. Work is remote or hybrid (Warsaw) within Agile, distributed teams. 🗂️ Requirements: Mastery of Java 17+, Proficiency in Spring, Spring Boot, Spring Security, Experience in cloud-native application development, Experience with Maven, Experience with SQL databases, Proficiency in Git and GitHub including pipeline development, Knowledge of JUnit, AssertJ, Hamcrest, Experience with CI/CD tools and processes, Experience with Kubernetes and Helm, Bash/Shell scripting skills, Experience in enterprise environments, Experience working in Agile (Scrum/Kanban) teams 📃 Skills: Java, Spring, SpringBoot, SpringSecurity, Maven, SQL, Git, GitHub, JUnit, AssertJ, Hamcrest, CICD, Kubernetes, Helm, Bash, Shell, Docker 🏢 Description: Type of work : Full-time; Remote/Hybrid (Warsaw) As a Senior Java Developer, you will lead the design, development, and maintenance of high-performance backend systems. You’ll collaborate with product managers, architects, and developers to ensure our solutions are scalable, secure, and future-ready. We encourage the use of Generative AI tools like GitHub Copilot to boost innovation and productivity. Requirements Java, Postgresql, Liquibase, Spring boot, Angular. Responsibilities Develop robust, configurable applications using Java 17+ and Spring Boot to effectively meet the diverse requirements of multiple customers. Ensure the efficiency of PostgreSQL databases for scalable solutions. Ensure security, scalability, and performance in all backend solutions. Employ Bash/Shell scripting for automation and comprehensive system integration tasks. Contribute to application deployment using Docker and Kubernetes , while utilizing Helm for package management. Communicate effectively in English (B2/C1 level) within distributed teams. Participate actively in scrum events. Collaborate with other engineering teams. Lead design discussions and mentor other developers. Client A global leader with a sharp focus on lottery solutions. A confident step forward building on a long history of delivering safe and secure technology, demonstrating strong commitment to customers as a dedicated lottery service provider. Leveraging collective insight, experience, and expertise to create reliable and engaging solutions that help lottery clients achieve objectives, meet player needs, and deliver meaningful benefits to communities.

🏢 Summary: Senior Backend Java Developer role focused on designing and building scalable, high-performance backend systems using Java and Spring Boot in a cloud-native environment. The position involves developing enterprise-grade solutions, ensuring performance and security, and supporting containerized deployments. The role requires strong experience with modern backend technologies and infrastructure tools. 🗂️ Requirements: 8+ years of backend development experience, Strong experience with Java 17+, Strong experience with Spring and Spring Boot, Experience with Spring Security, Experience with SQL databases, Experience with Maven, Experience with Git and CI/CD pipelines, Experience with testing frameworks (JUnit, AssertJ, Hamcrest), Experience with Kubernetes and Helm, Experience with Bash or Shell scripting, Experience with cloud-native applications, Experience in enterprise environments 📃 Skills: Java, Spring, SpringBoot, SpringSecurity, SQL, Maven, Git, CICD, JUnit, AssertJ, Hamcrest, Kubernetes, Helm, Bash, Shell, Docker, PostgreSQL 🏢 Description: Senior Backend Java Developer Location: Warsaw, Poland (hybrid – 2 days/week in the office) About the Role We’re looking for a Senior Backend Java Developer to design and build scalable, high-performance backend systems for international products. You’ll work in a collaborative environment, contribute to architectural decisions, and mentor other engineers. Responsibilities Design, develop, and maintain backend systems using Java 17+ and Spring Boot Ensure scalability, performance, and security of solutions Work with SQL databases (e.g. PostgreSQL) Support deployments using Docker, Kubernetes, and Helm Use Bash/Shell for automation and integration tasks Lead technical discussions and mentor team members Collaborate in Agile (Scrum) teams and communicate in English Requirements Strong experience with Java 17+, Spring / Spring Boot / Spring Security Experience with cloud-native applications Maven, SQL, Git (GitHub, CI/CD) Testing frameworks (JUnit, AssertJ, Hamcrest) Kubernetes, Helm Bash/Shell scripting English B2/C1 Experience in enterprise environments 8+ years of backend development experience Nice to Have PostgreSQL, Hibernate/JPA Kafka, event-driven architecture Microservices architecture Python Knowledge of C or Go CI/CD tools, JIRA Monitoring tools (Grafana, Prometheus, Kibana) Security best practices (OWASP) Qualifications Degree in Computer Science or related field

🏢 Summary: Senior Java Developer role focused on building and optimizing scalable backend systems for real-time data processing in a fully remote environment. The position involves developing Java 17+ and Spring Boot applications, managing Kafka streams, implementing CI/CD pipelines, and maintaining high-quality testing and database solutions. 🗂️ Requirements: 5+ years of Java development experience, Java 17+ proficiency, Spring Boot expertise, REST API design experience, Apache Kafka experience, JUnit knowledge, Mockito knowledge, CI/CD experience, Jenkins familiarity or GitLab CI familiarity, Good Polish language skills, Communicative English level, Legal right to work in the European Union 📃 Skills: Java, Spring, Kafka, JUnit, Mockito, REST, Jenkins, GitLab, PostgreSQL, RabbitMQ, OpenShift, Prometheus, Grafana, JMeter 🏢 Description: Unleash innovative backend solutions — shape the future of real-time data processing! 100% remote work. As a Senior Java Developer, you will be working for a client focused on building robust, scalable software solutions. You will contribute to advancing data-driven platforms, delivering impactful backend components that support critical business operations and digital transformation. Your main responsibilities: - Develop and optimize Java 17+ applications with Spring Boot, focusing on REST API creation and integration. - Design and write automated tests, including unit, integration, contract, and API testing using JUnit, Mockito, and REST Assured. - Manage Apache Kafka streams, ensuring seamless real-time data processing and system reliability. - Implement CI/CD pipelines with Jenkins or GitLab CI to improve development workflows. - Maintain and enhance PostgreSQL database solutions, ensuring data integrity and performance. - Collaborate across teams to troubleshoot and resolve complex technical issues. - Document technical specifications and participate in code reviews. You’re ideal for this role if you have: - At least 5 years of professional experience in Java development. - Advanced knowledge of Java 17+, Spring Boot, and REST API design. - Proven expertise with Apache Kafka. - Experience with testing frameworks such as JUnit and Mockito. - Familiarity with CI/CD tools like Jenkins or GitLab CI. Nice to have: - Working knowledge of PostgreSQL and RabbitMQ. - Experience with OpenShift, Prometheus, Grafana, or JMeter. Language requirements: - Polish: Good command. - English: Communicative level. Eligibility: - Only candidates with an existing legal right to work in the European Union will be considered. Interested candidates should apply with a CV, preferably in English, including consent to the processing and storage of personal data.

🏢 Summary: Senior Java Developer contract for a logistics project, focused on building secure, high-performance backend data-processing services in a microservices architecture. The role uses Java, Confluent Kafka/KStreams, MongoDB Atlas and PostgreSQL, with hybrid work from the Warsaw office 2–3 days per week. 🗂️ Requirements: 10+ years of Java development experience, Strong Confluent Kafka expertise, Strong KStreams expertise, MongoDB Atlas experience, PostgreSQL experience, English proficiency, Polish proficiency 📃 Skills: Java, Kafka, Confluent, KStreams, MongoDB, PostgreSQL, CI/CD, Microservices 🏢 Description: Work model: 2–3 days a week from the Warsaw office Rate: B2B, up to 190 zł/h Start: ASAP or within 1 month Project length: More than 12 months, with extensions Project language: English and Polish Industry: Logistics Recruitment process: 2 interviews with the client Workload: Full-time Summary The Senior Java Developer is primarily responsible for designing and developing backend applications while ensuring high standards of security, performance, and quality. The role focuses on leveraging extensive Java and Kafka experience to build robust data-processing solutions within a microservices architecture. Main Responsibilities - Build, test, and deploy software using CI/CD pipelines. - Create microservices for data processing, database interactions, and data exposure. - Implement relevant architectural patterns for data handling and web services. - Ensure accurate logging and alert configurations for operational efficiency. - Conduct comprehensive software testing against various performance criteria. - Integrate security features, including authentication and authorization controls. - Participate in a developer guild to share best practices and technical knowledge. Key Requirements - 10+ years of relevant Java development experience. - Strong Kafka expertise, particularly Confluent Kafka and KStreams. - Experience with MongoDB Atlas and PostgreSQL. Nice to Have - Familiarity with OIDC, OAuth2, and SAML authentication protocols. - Experience with Docker containerization. - Knowledge of Kubernetes container orchestration. - Experience with the ELK stack for logging, monitoring, and alerting.

🏢 Summary: Long-term B2B Senior Java Developer contract for building secure, high-performance backend data-processing solutions in a microservices architecture. The role involves Java and Kafka development, CI/CD delivery, database integration, testing, monitoring, and security implementation in a hybrid work model. 🗂️ Requirements: 10+ years of Java development experience, Strong Kafka expertise, Experience with Confluent Kafka, Experience with KStreams, Experience with MongoDB Atlas, Experience with PostgreSQL 📃 Skills: Java, Kafka, Confluent, KStreams, MongoDB, PostgreSQL, Microservices, CICD 🏢 Description: Rate: 180–200 PLN/h Work mode: Hybrid, 2–3 days per week in the office Summary The Senior Java Developer is responsible for designing and developing backend applications while ensuring high standards of security, performance, and quality. The role focuses on using extensive Java and Kafka experience to build robust data-processing solutions within a microservices architecture. Main Responsibilities - Build, test, and deploy software using CI/CD pipelines. - Create microservices for data processing, database interactions, and data exposure. - Implement relevant architectural patterns for data handling and web services. - Ensure accurate logging and alert configurations for operational efficiency. - Conduct comprehensive software testing against various performance criteria. - Integrate security features, including authentication and authorization controls. - Participate in a developer guild to share best practices and technical knowledge. Key Requirements - 10+ years of relevant Java development experience. - Strong Kafka expertise, particularly with Confluent Kafka and KStreams. - Experience with MongoDB Atlas and PostgreSQL. Nice to Have - Familiarity with OIDC, OAuth2, and SAML authentication protocols. - Experience with Docker. - Knowledge of Kubernetes. - Experience with the ELK stack for logging, monitoring, and alerting.

🏢 Summary: Senior Java Developer role focused on building and maintaining scalable microservices and cloud-based digital products in the OTT/ECommerce industry within an Agile environment. The position involves backend development, architectural contributions, CI/CD support, and collaboration with cross-functional teams using modern Java and cloud technologies. Hybrid or remote work model based in Warszawa. 🗂️ Requirements: 4+ years of Java development experience, Java 8-25, Multithreading, Immutability, Design patterns, Spring Boot, Spring MVC, WebFlux, MyBatis, TestContainers, SQL, NoSQL databases, Oracle, PostgreSQL, MongoDB, Redis, Kafka, Microservices architecture, RESTful APIs, Kubernetes, Docker, AWS, JUnit, Mockito, Spock, Jenkins, GitLab, Unix/Linux scripting, Polish language proficiency, Communicative English, Legal right to work in the EU 📃 Skills: Java, Spring, WebFlux, MyBatis, TestContainers, SQL, Oracle, PostgreSQL, MongoDB, Redis, Kafka, REST, Kubernetes, Docker, AWS, JUnit, Mockito, Spock, Jenkins, GitLab, Unix, Linux, SCRUM, Confluence, Git 🏢 Description: Empower digital transformation — craft scalable solutions with Java and cloud innovation! Warszawa-based opportunity with hybrid/ remote work model. As a Senior Java Developer , you will be working for our client, a leading player in the OTT/ECommerce industry, focused on delivering cutting-edge digital products within a dynamic and collaborative environment. Be part of a team that drives innovation, shapes future-ready architectures, and elevates user experiences through advanced microservices and cloud technologies. Your main responsibilities: Develop and maintain robust microservices using Java 8-25, ensuring high-quality code and optimal performance. Collaborate with cross-functional teams including Frontend Developers and Test Engineers within an Agile Nexus SCRUM framework. Conduct code reviews, contribute to architectural decisions, and mentor junior team members. Design, implement, and optimize RESTful architecture, utilizing tools like Kubernetes, Docker, and SOA principles. Support CI/CD pipelines and manage version control with Git, Jenkins, and related tools. Write comprehensive technical documentation in Confluence and contribute to knowledge sharing. Participate in technical consultations, problem-solving, and continuous improvement initiatives. Ensure application security following OWASP standards and best practices. You're ideal for this role if you have: At least 4 years of professional experience in Java development. Strong expertise in Java 8-25, multithreading, immutability, and design patterns. Experience with Spring Boot, Spring MVC, WebFlux, MyBatis, and TestContainers. Solid knowledge of SQL and NoSQL databases such as Oracle, PostgreSQL, MongoDB, Redis, and messaging systems like Kafka. Familiarity with microservices architecture, RESTful APIs, Kubernetes, Docker, and cloud services (AWS). Practical understanding of testing frameworks like JUnit, Mockito, and Spock. Experience with version control, CI/CD tools (Jenkins, GitLab), and scripting in Unix/Linux environments. Good command of the Polish language and communicative English skills. Ability to work independently with strong analytical and problem-solving skills. It is a strong plus if you have: Front-end skills (HTML, CSS, JavaScript, Angular/React/Vue.js). Certifications in AWS or other cloud platforms. Knowledge of DevOps practices and automation tools. Eligibility to work in the European Union: Only candidates with an existing legal right to work in the EU will be considered for this role. #MAKEYourCareerBETTER Interested? Apply now and include your CV (preferably in English) along with a statement confirming your consent to the processing and storage of your personal data.

🏢 Summary: Senior Java Developer role focused on building and maintaining Java backend applications within a center of excellence, contributing to architecture decisions and CI/CD processes. The position involves working in a collaborative, non-hierarchical environment and mentoring junior developers. It requires strong backend expertise and active participation in modern microservices-based architectures. 🗂️ Requirements: Higher education degree, 5+ years of Java backend development experience, Strong knowledge of Spring and Spring Boot, Experience with relational databases (Oracle, PostgreSQL), Proficiency in SQL, Experience with JPA and Hibernate, Knowledge of microservices-based architecture, Experience with CI/CD tools and processes, English proficiency at B2 level 📃 Skills: Java, Spring, SpringBoot, SQL, Oracle, PostgreSQL, JPA, Hibernate, Microservices, CI/CD, Angular, AWS 🏢 Description: Summary: The role of a Senior Java Developer involves contributing to the establishment of a center of excellence within a leading multinational company. The primary goal is to leverage strong Java development skills in a collaborative, innovative environment while mentoring junior developers. Responsibilities: * Join the establishment of a center of excellence. * Develop and maintain Java backend applications. * Mentor and coach junior team members (Senior role). * Facilitate onboarding and serve as a role model (Lead role). * Collaborate in a horizontal organization with no management hierarchy. * Engage in CI/CD practices and application architecture discussions. Must Haves: * Higher education degree. * Strong experience with Java Backend development (5+ years). * Proficiency in Spring/Spring Boot framework. * Experience with Relational Database Management Systems (Oracle, PostgreSQL, SQL). * Familiarity with JPA and Hibernate. * Knowledge of Application architecture (Microservices based, hexagonal…). * Proficiency in CI/CD tools. * English proficiency at B2 level. Nice to Haves: * Experience with Java Frontend frameworks (Angular or similar). * Familiarity with AWS or other cloud platforms. * Problem-solving skills and logical reasoning. * Passion for continuous learning and growth. * Experience in Agile environments and Scrum methodologies. Other Details: * Work Model: 4 days in-office initially, transitioning to 3 days in-office and 2 days remote. * Work Schedule: 43 hours/week in winter and 39 hours/week in summer with additional compensation days.

🏢 Summary: Senior Java Developer role focused on building and maintaining Java backend applications within a newly established center of excellence in a multinational environment. The position combines hands-on backend development with mentoring responsibilities, active participation in architecture discussions, and CI/CD practices. It offers a collaborative, non-hierarchical setup with a hybrid work model. 🗂️ Requirements: Higher education degree, 5+ years of experience in Java Backend development, Strong proficiency in Spring and Spring Boot, Experience with relational databases (Oracle, PostgreSQL, SQL), Experience with JPA and Hibernate, Knowledge of microservices-based and hexagonal architecture, Experience with CI/CD tools and practices, English proficiency at B2 level 📃 Skills: Java, Spring, SpringBoot, Oracle, PostgreSQL, SQL, JPA, Hibernate, Microservices, HexagonalArchitecture, CICD, Angular, AWS, Scrum, Agile 🏢 Description: Summary: The role of a Senior Java Developer involves contributing to the establishment of a center of excellence within a leading multinational company. The primary goal is to leverage strong Java development skills in a collaborative, innovative environment while mentoring junior developers. Responsibilities: * Join the establishment of a center of excellence. * Develop and maintain Java backend applications. * Mentor and coach junior team members (Senior role). * Facilitate onboarding and serve as a role model (Lead role). * Collaborate in a horizontal organization with no management hierarchy. * Engage in CI/CD practices and application architecture discussions. Must Haves: * Higher education degree. * Strong experience with Java Backend development (5+ years). * Proficiency in Spring/Spring Boot framework. * Experience with Relational Database Management Systems (Oracle, PostgreSQL, SQL). * Familiarity with JPA and Hibernate. * Knowledge of Application architecture (Microservices based, hexagonal…). * Proficiency in CI/CD tools. * English proficiency at B2 level. Nice to Haves: * Experience with Java Frontend frameworks (Angular or similar). * Familiarity with AWS or other cloud platforms. * Problem-solving skills and logical reasoning. * Passion for continuous learning and growth. * Experience in Agile environments and Scrum methodologies. Other Details: * Work Model: 4 days in-office initially, transitioning to 3 days in-office and 2 days remote. * Work Schedule: 43 hours/week in winter and 39 hours/week in summer with additional compensation days.

🏢 Summary: Opportunity for a Senior Java Backend Developer to build and maintain a secure, large-scale public platform based on microservices within the financial services sector. The role focuses on developing business-critical backend services, contributing to architectural decisions, and improving deployment and engineering practices. Ideal for experienced engineers who combine strong Java expertise with architectural thinking and a proactive approach to system optimization. 🗂️ Requirements: 6–10 years of professional software development experience, Strong expertise in Java backend development, Experience with microservices architecture, Understanding of distributed systems, Experience in system design and software architecture, Ability to work with secure, large-scale systems, Experience improving deployment processes and system reliability 📃 Skills: Java, Microservices, DistributedSystems, SystemDesign, SoftwareArchitecture, REST, Git, Maven, Gradle, Python, Cloud, DevOps 🏢 Description: Senior Java Backend Developer 📍 Location: Wrocław, Poland (Hybrid – 3 days onsite) 📈 Experience: 6–10 years We are currently looking for an experienced Java Backend Developer for our client operating in the financial services sector . The successful candidate will join a team responsible for developing and maintaining a secure, large-scale public platform built on a microservices architecture. This role offers the opportunity to work on business-critical systems where reliability, scalability, and security are key priorities. Beyond feature development, the team is focused on addressing challenges related to architecture, deployment practices, and engineering processes. Therefore, we are looking for someone who combines strong hands-on development skills with architectural thinking and a proactive approach to problem-solving. Key Responsibilities Design and develop new backend features and services using Java Maintain and enhance a secure, customer-facing platform Work within a modern microservices ecosystem Contribute to architectural improvements and technical decision-making Help optimize deployment processes, system reliability, and development workflows Identify technical challenges and propose scalable, long-term solutions What We're Looking For 6–10 years of professional software development experience Strong expertise in Java backend development Solid understanding of microservices architecture and distributed systems Experience with system design and software architecture Strong analytical and critical-thinking skills Ability to understand technical concepts deeply and make informed engineering decisions A proactive mindset and willingness to improve existing systems, processes, and practices Nice to Have Experience with Python Exposure to cloud environments and modern DevOps practices This opportunity is particularly suited to engineers who enjoy working on complex backend systems, influencing architectural decisions, and helping teams improve the way software is designed, built, and deployed.

🏢 Summary: Senior Java Developer role focused on designing and building high-performance, scalable backend systems in a distributed microservices environment for the financial sector. The position involves developing REST APIs, processing large data volumes, and contributing to architecture and CI/CD in cloud-based environments. The role requires strong expertise in Java, Spring, distributed systems, and Kubernetes. 🗂️ Requirements: Minimum 10 years of software development experience, Very good knowledge of Java and Spring, Strong understanding of REST APIs, HTTPS, microservices, and message queues, Ability to design high-availability, scalable, high-performance systems, Very good knowledge of relational databases and SQL, Knowledge of distributed systems and data processing, Hands-on experience with Kubernetes and cloud platforms (GCP preferred), Familiarity with CI/CD pipelines, Experience working in Agile methodologies, Fluent Polish and English, Residence in Poland 📃 Skills: Java, Spring, REST, HTTPS, Microservices, MQ, SQL, Kubernetes, GCP, CI/CD, Agile, DistributedSystems, DataProcessing 🏢 Description: We are looking for an experienced Senior Java Developer to join a team responsible for building and developing modern backend systems in a distributed environment. The projects involve high-performance and scalable solutions used in the financial sector, with a focus on processing large volumes of data and microservices architecture. Your tasks Designing and developing backend systems based on Java Creating and evolving a microservices architecture Building and maintaining REST APIs and system integrations Designing solutions that meet high availability and performance requirements Working with systems that process large volumes of data Collaborating with the team using Agile methodologies Participating in architecture design and technical decision-making Implementing and optimizing CI/CD processes and ensuring system security Requirements Minimum 10 years in software development Very good knowledge of Java (backend) and Spring Strong understanding of REST APIs, HTTPS, microservices, and message queues (MQ) Ability to design high-availability, scalable, and high-performance systems Very good knowledge of relational databases (SQL) Familiarity with CI/CD pipelines and Agile ways of working Knowledge of distributed systems and data processing Hands-on work with Kubernetes and cloud platforms (GCP preferred) Fluent Polish and English required Residing in Poland required Nice-to-have requirements Knowledge of Go, Rust, or similar system-level languages Experience with NoSQL and analytical databases, e.g., ClickHouse Frontend development experience Familiarity with the banking sector (trade lifecycle, FX, post-trade processing) Banking experience / FX experience (forex) Working from the office in Krakow 6 times per month What we offer Great Place to Work since 2015 - it’s thanks to feedback from our workers that we get this special title and constantly implement new ideas Employment stability - revenue of PLN 2.1BN, no debts, since 2006 on the market We share the profit with Workers - over PLN 76M has already been allocated for this aim since 2022 Attractive benefits package - private healthcare, benefits cafeteria platform, car discounts and more Comfortable workplace – class A offices or remote work Dozens of fascinating projects for prestigious brands from all over the world PLN 1 000 000 per year for your ideas - with this amount, we support the passions and voluntary actions of our workers Investment in your growth – meetups, webinars, training platform and technology blog – you choose Fantastic atmosphere created by all Sii Power People If you want to work on systems with high operational significance — apply now!