Senior Java Developer

🏢 Summary: B2B Senior Java Developer role focused on designing, implementing, and modernizing a large-scale Terminal Management System managing 300,000+ payment terminals within a distributed architecture. The position involves working with Spring-based microservices, WildFly applications, messaging systems, and complex integrations while supporting migration from a legacy system. The role includes system upgrades, legacy code refactoring, security remediation, and development in a hybrid work model in Warsaw. 🗂️ Requirements: Full availability in Polish time zone, Onsite work in Warsaw 4 days per week, Very good knowledge of Java 8+, Strong object-oriented programming skills, Experience in independent design and implementation of application components, Strong experience with Spring and Spring Boot, Strong experience with Hibernate/JPA and JEE, Practical experience with RabbitMQ or other message queues, Experience with Maven, Git, GitLab, Jenkins, Nexus, Knowledge of CI/CD pipelines, Good knowledge of Oracle or other relational databases, Experience in RESTful API design, Experience with distributed systems and system integration, Experience with JBoss or WildFly application servers, Knowledge of security scanning tools, English level B2 or higher 📃 Skills: Java, Spring, SpringBoot, Hibernate, JPA, JEE, RabbitMQ, Maven, Git, GitLab, Jenkins, Nexus, Jira, Oracle, SQL, REST, SOAP, RMI, WildFly, JBoss, Hazelcast, GWT, GWTExt, Fortify, Sonatype 🏢 Description: Senior Java Developer (TMS) Location: Warsaw, Poland Work model: Hybrid (4 days onsite / 1 day remote per week) Time zone: Polish time zone Contract type: B2B About the Project The Terminal Management System (TMS) is a large-scale platform used to manage over 300,000 payment terminals, providing a unified way to operate devices from multiple hardware vendors. The system has a complex, distributed architecture consisting of: TMS – a WildFly-based application providing GUI and selected business functionalities RTMS – three Spring Boot–based services implementing most of the business logic A gradual migration from TMS to RTMS is currently in progress. The platform makes extensive use of Spring, Hibernate, RabbitMQ, distributed transactions (2PC, Saga patterns), and distributed cache (Hazelcast). It is integrated with multiple internal and external systems via REST, SOAP, RMI, and direct database connections. The GUI layer is implemented using GWT and GWTExt. Responsibilities Design and implement IT solutions based on analytical and technical documentation Review analytical documentation and propose technical improvements Create and maintain technical documentation Perform technical upgrades of existing systems Work with and refactor legacy code Conduct regular application security scans and remove identified vulnerabilities Requirements Full availability in the Polish time zone Ability to work from the Warsaw office (4 days onsite + 1 day WFH weekly) Very good knowledge of Java 8+ and object-oriented programming Experience in independent design, implementation, documentation, and testing of application components Strong hands-on experience with Spring, Spring Boot, Hibernate/JPA, and JEE Practical experience with message queue systems, especially RabbitMQ Hands-on knowledge of development and CI/CD tools: Maven, Git, GitLab, GitLab CI/CD, Jenkins, Nexus, Jira Good knowledge of relational databases, particularly Oracle Practical experience in RESTful API design Experience with system integration and distributed systems Experience with application servers such as JBoss / WildFly Knowledge of security scanning tools (e.g. Fortify, Sonatype) English proficiency at B2 level or higher Benefits B2B contract Access to training and e‑learning platforms Sports card (e.g. Multisport) Private healthcare Opportunity to work on a large-scale, mission‑critical system Hybrid work model and a modern office in Warsaw

🏢 Summary: The role combines Senior Java Development (70%) with system analysis (30%) for a complex Terminal Management System managing 300k+ payment terminals. It involves designing, upgrading and integrating distributed system components, working with legacy code, and supporting migration to Spring Boot-based architecture. The project includes system integration, reverse engineering, automated testing and vulnerability remediation in a large-scale enterprise environment. 🗂️ Requirements: Very good knowledge of Java 8+ (17–21), Strong object-oriented programming knowledge, Experience in independent design, implementation, documentation and testing of application components, Very good practical knowledge of Spring and Spring Boot, Very good practical knowledge of Hibernate/JPA and JEE, Strong SQL knowledge, Knowledge of relational databases, especially Oracle, Experience with message queue systems (RabbitMQ), Practical knowledge of RESTful API design, Experience with distributed systems, Experience with system integration, Experience with application servers (JBoss/WildFly), Knowledge of Maven, Git, GitLab, GitLab CI/CD, Jenkins, Nexus, Jira, Knowledge of Scrum methodology, Knowledge of scanning tools (Fortify, Sonatype), Ability to work from Warsaw office 4 days per week 📃 Skills: Java, Spring, SpringBoot, Hibernate, JPA, JEE, SQL, Oracle, RabbitMQ, REST, Maven, Git, GitLab, Jenkins, Nexus, Jira, JBoss, WildFly, Hazelcast, SOAP, RMI, GWT, GWTExt, Fortify, Sonatype, Scrum 🏢 Description: Analyst (70%) Senior Java Developer (30%) Terminal Management System •         Design and implementation of IT solutions based on the presented analytical and technical documentation; •         Reviewing analytical documentation; •         Creating technical documentation; • Technical upgrade for existing system; • Working with legacy code • Reverse engineering based on: o existing source code o existing functional and technical documentation o collected and documented business processes, o user interface to the system and accessing databases • Defining and building test cases for automatic tests Job Requirements • Ability to work from the office in Warsaw (weekly: 4 days at office + 1 day remotely); • Very good knowledge of Java 8+ (17 - 21) and object-oriented programming issues; • Experience in independent design, implementation, documentation and testing of application components; • Very good and p ractical knowledge of Spring, Spring Boot, SQL, Scrum, Hibernate/JPA and JEE frameworks; • Practical knowledge with message queue systems, particularly RabbitMQ; • Practical knowledge of tools supporting the software development process: Maven, Git, Gitlab, Gitlab CI/CD, Jenkins, Nexus, Jira; • Knowledge of relational databases, in particular Oracle; • Practical knowledge of RESTful API design; • Experience in system integration; • Experience with distributed systems; • Experience with application servers, JBoss/WildFly; ·  Knowledge of scanning tools (Fortify, Sonatype..) • Knowledge of English / B2; Nice to have : ·         Angular ·         Linux server ·         Docker Description of the area of involvement TMS (Terminal Management System) is used to manage a very large number of payment terminals (300k+), it gives users a uniform way to manage different terminals from different hardware vendors. TMS has a complex architecture, consisting of two components TMS (1 WildFly instance) providing GUI and implementing some business functions and RTMS (3 Spring-boot instances) implementing most of the business functionalities. A gradual migration from TMS to RTMS is being carried out. The system intensively uses Spring, Hibernate and RabbitMQ. The system has distributed transactions (different two-phase-commit, saga approaches) and distributed cache (Hazelcast). TMS is integrated with many internal and external systems (via REST, SOAP, RMI, direct database connections and database links). The GUI is written in GWT and GWTExt. TMS is subjected to regular application scans and vulnerabilities removal 1 year project with possibility for hiring after this time.

🏢 Summary: Role combining business analysis and senior Java development for a large-scale Terminal Management System, focused on designing, upgrading, integrating, and maintaining distributed enterprise applications. The project involves legacy system modernization, reverse engineering, automated testing, and work with complex integrations and distributed transactions. Hybrid work model in Warsaw with a 1-year contract and potential long-term hiring. 🗂️ Requirements: Work from Warsaw office 4 days per week, Java 8+, Object-oriented programming, Spring, Spring Boot, SQL, Scrum, Hibernate, JPA, JEE, RabbitMQ, Maven, Git, GitLab, CI/CD, Jenkins, Nexus, Jira, Oracle, REST, System integration, Distributed systems, JBoss, WildFly, Fortify, Sonatype, English B2, Experience in design and implementation of application components, Experience with documentation and testing 📃 Skills: Java, Spring, SpringBoot, SQL, Scrum, Hibernate, JPA, JEE, RabbitMQ, Maven, Git, GitLab, Jenkins, Nexus, Jira, Oracle, REST, JBoss, WildFly, Fortify, Sonatype, Hazelcast, SOAP, RMI, GWT, GWTExt, Angular, Linux, Docker 🏢 Description: Analyst (70%) Senior Java Developer (30%) Terminal Management System •         Design and implementation of IT solutions based on the presented analytical and technical documentation; •         Reviewing analytical documentation; •         Creating technical documentation; • Technical upgrade for existing system; • Working with legacy code • Reverse engineering based on: o existing source code o existing functional and technical documentation o collected and documented business processes, o user interface to the system and accessing databases • Defining and building test cases for automatic tests Job Requirements • Ability to work from the office in Warsaw (weekly: 4 days at office + 1 day remotely); • Very good knowledge of Java 8+ (17 - 21) and object-oriented programming issues; • Experience in independent design, implementation, documentation and testing of application components; • Very good and p ractical knowledge of Spring, Spring Boot, SQL, Scrum, Hibernate/JPA and JEE frameworks; • Practical knowledge with message queue systems, particularly RabbitMQ; • Practical knowledge of tools supporting the software development process: Maven, Git, Gitlab, Gitlab CI/CD, Jenkins, Nexus, Jira; • Knowledge of relational databases, in particular Oracle; • Practical knowledge of RESTful API design; • Experience in system integration; • Experience with distributed systems; • Experience with application servers, JBoss/WildFly; ·  Knowledge of scanning tools (Fortify, Sonatype..) • Knowledge of English / B2; Nice to have : ·         Angular ·         Linux server ·         Docker Description of the area of involvement TMS (Terminal Management System) is used to manage a very large number of payment terminals (300k+), it gives users a uniform way to manage different terminals from different hardware vendors. TMS has a complex architecture, consisting of two components TMS (1 WildFly instance) providing GUI and implementing some business functions and RTMS (3 Spring-boot instances) implementing most of the business functionalities. A gradual migration from TMS to RTMS is being carried out. The system intensively uses Spring, Hibernate and RabbitMQ. The system has distributed transactions (different two-phase-commit, saga approaches) and distributed cache (Hazelcast). TMS is integrated with many internal and external systems (via REST, SOAP, RMI, direct database connections and database links). The GUI is written in GWT and GWTExt. TMS is subjected to regular application scans and vulnerabilities removal 1 year project with possibility for hiring after this time.

🏢 Summary: 1-year project for a Senior Java Developer to design, implement, upgrade, and maintain a complex Terminal Management System handling 300k+ payment terminals. The role involves working with legacy code, distributed systems, system integrations, and ensuring application security through regular vulnerability scans. The system is based on Java and Spring ecosystem with intensive use of messaging and transactional mechanisms. 🗂️ Requirements: Very good knowledge of Java 8+, Strong understanding of object-oriented programming, Experience in designing and implementing application components, Practical knowledge of Spring and Spring Boot, Practical knowledge of SQL and relational databases, Experience with Hibernate and JPA, Knowledge of JEE frameworks, Experience with RabbitMQ or other message queues, Knowledge of Maven and Git, Experience with Gitlab and CI/CD pipelines, Experience with Jenkins and Nexus, Knowledge of Oracle database, Experience in RESTful API design, Experience in system integration, Experience with distributed systems, Experience with JBoss or WildFly, Knowledge of security scanning tools (Fortify, Sonatype) 📃 Skills: Java, Spring, SpringBoot, SQL, Hibernate, JPA, JEE, RabbitMQ, Maven, Git, Gitlab, CICD, Jenkins, Nexus, Jira, Oracle, REST, JBoss, WildFly, Fortify, Sonatype, Hazelcast, GWT, GWTExt, SOAP, RMI 🏢 Description: Senior Java Developer (TMS) •         Design and implementation of IT solutions based on the presented analytical and technical documentation; •         Reviewing analytical documentation; •         Creating technical documentation; •         Technical upgrade for existing system; •         Working with legacy code •         Conducting regular scans in the application and removing vulnerabilities Job Requirements • Fully available in the Polish time zone; • Ability to work from the office in Warsaw (weekly: 4 days at office + 1 day remotely); • Very good knowledge of Java 8+ and object-oriented programming issues; • Experience in independent design, implementation, documentation and testing of application components; • Very good and p ractical knowledge of Spring, Spring Boot, SQL, Scrum, Hibernate/JPA and JEE frameworks; • Practical knowledge with message queue systems, particularly RabbitMQ; • Practical knowledge of tools supporting the software development process: Maven, Git, Gitlab, Gitlab CI/CD, Jenkins, Nexus, Jira; • Knowledge of relational databases, in particular Oracle; • Practical knowledge of RESTful API design; • Experience in system integration; • Experience with distributed systems; • Experience with application servers, JBoss/WildFly; ·  Knowledge of scanning tools (Fortify, Sonatype..) • Knowledge of English / B2; Nice to have: ·         Angular ·         Linux server ·         Docker Description of the area of involvement TMS (Terminal Management System) is used to manage a very large number of payment terminals (300k+), it gives users a uniform way to manage different terminals from different hardware vendors. TMS has a complex architecture, consisting of two components TMS (1 WildFly instance) providing GUI and implementing some business functions and RTMS (3 Spring-boot instances) implementing most of the business functionalities. A gradual migration from TMS to RTMS is being carried out. The system intensively uses Spring, Hibernate and RabbitMQ. The system has distributed transactions (different two-phase-commit, saga approaches) and distributed cache (Hazelcast). TMS is integrated with many internal and external systems (via REST, SOAP, RMI, direct database connections and database links). The GUI is written in GWT and GWTExt. 1 year project with possibility for hiring after this time.

🏢 Summary: Senior Java Developer role focused on designing, implementing, and maintaining a large-scale Terminal Management System handling 300k+ payment terminals. The position involves working with distributed systems, legacy code, system integrations, and security vulnerability remediation in a hybrid Warsaw-based setup. The project includes migration from legacy architecture to Spring Boot-based services with potential long-term hiring after the initial one-year contract. 🗂️ Requirements: Availability in the Polish time zone, Ability to work from the Warsaw office 4 days per week, Java 8+ proficiency, Object-oriented programming knowledge, Experience designing and implementing application components, Experience documenting and testing application components, Spring knowledge, Spring Boot knowledge, SQL knowledge, Scrum knowledge, Hibernate/JPA knowledge, JEE knowledge, RabbitMQ experience, Maven knowledge, Git knowledge, GitLab knowledge, GitLab CI/CD knowledge, Jenkins knowledge, Nexus knowledge, Jira knowledge, Oracle database knowledge, RESTful API design experience, System integration experience, Distributed systems experience, JBoss/WildFly experience, Fortify knowledge, Sonatype knowledge, English level B2 📃 Skills: Java, Spring, SpringBoot, SQL, Scrum, Hibernate, JPA, JEE, RabbitMQ, Maven, Git, GitLab, Jenkins, Nexus, Jira, Oracle, REST, JBoss, WildFly, Fortify, Sonatype, Hazelcast, SOAP, RMI, GWT, GWTExt, Angular, Linux, Docker 🏢 Description: Senior Java Developer (TMS) •         Design and implementation of IT solutions based on the presented analytical and technical documentation; •         Reviewing analytical documentation; •         Creating technical documentation; •         Technical upgrade for existing system; •         Working with legacy code •         Conducting regular scans in the application and removing vulnerabilities Job Requirements • Fully available in the Polish time zone; • Ability to work from the office in Warsaw (weekly: 4 days at office + 1 day remotely); • Very good knowledge of Java 8+ and object-oriented programming issues; • Experience in independent design, implementation, documentation and testing of application components; • Very good and p ractical knowledge of Spring, Spring Boot, SQL, Scrum, Hibernate/JPA and JEE frameworks; • Practical knowledge with message queue systems, particularly RabbitMQ; • Practical knowledge of tools supporting the software development process: Maven, Git, Gitlab, Gitlab CI/CD, Jenkins, Nexus, Jira; • Knowledge of relational databases, in particular Oracle; • Practical knowledge of RESTful API design; • Experience in system integration; • Experience with distributed systems; • Experience with application servers, JBoss/WildFly; ·  Knowledge of scanning tools (Fortify, Sonatype..) • Knowledge of English / B2; Nice to have: ·         Angular ·         Linux server ·         Docker Description of the area of involvement TMS (Terminal Management System) is used to manage a very large number of payment terminals (300k+), it gives users a uniform way to manage different terminals from different hardware vendors. TMS has a complex architecture, consisting of two components TMS (1 WildFly instance) providing GUI and implementing some business functions and RTMS (3 Spring-boot instances) implementing most of the business functionalities. A gradual migration from TMS to RTMS is being carried out. The system intensively uses Spring, Hibernate and RabbitMQ. The system has distributed transactions (different two-phase-commit, saga approaches) and distributed cache (Hazelcast). TMS is integrated with many internal and external systems (via REST, SOAP, RMI, direct database connections and database links). The GUI is written in GWT and GWTExt. 1 year project with possibility for hiring after this time.

🏢 Summary: B2B contract for a Senior Java Developer to design, implement, and modernize a large-scale Terminal Management System handling 300k+ payment terminals. The role focuses on developing and migrating distributed systems components using Spring Boot and WildFly, integrating multiple internal and external services, and improving security through vulnerability scanning and upgrades. 🗂️ Requirements: Very good knowledge of Java 8+, Strong object-oriented programming skills, Experience in designing, implementing, documenting and testing application components, Very good practical knowledge of Spring and Spring Boot, Very good practical knowledge of Hibernate/JPA and JEE, Experience with message queue systems, especially RabbitMQ, Knowledge of Maven, Git, GitLab, GitLab CI/CD, Jenkins, Nexus, Jira, Knowledge of relational databases, particularly Oracle, Practical knowledge of RESTful API design, Experience in system integration, Experience with distributed systems, Experience with JBoss/WildFly application servers, Knowledge of security scanning tools (e.g., Fortify, Sonatype), Availability to work 4 days per week from Warsaw office, Full availability in Polish time zone 📃 Skills: Java, Spring, SpringBoot, Hibernate, JPA, JEE, RabbitMQ, Maven, Git, GitLab, Jenkins, Nexus, Jira, Oracle, REST, JBoss, WildFly, Fortify, Sonatype, Hazelcast, GWT, GWTExt, SOAP, RMI 🏢 Description: The client is an American multinational company in the fintech industry Key details: Location: 4 days/week from the Warsaw office Rate: 130–180 PLN/hour net + VAT Job type: B2B contract Duration: 12 months + extensions Recruitment process: 2 stages English and Polish: B2/B2+ Luxmed, MultiSport, equipment provided by the client Job Responsibilities Design and implementation of IT solutions based on the presented analytical and technical documentation; Reviewing analytical documentation; Creating technical documentation; Technical upgrade for existing system; Working with legacy code Conducting regular scans in the application and removing vulnerabilities Job Requirements Fully available in the Polish time zone; Ability to work from the office in Warsaw (weekly: 4 days at office + 1 day WFH ); Very good knowledge of Java 8+ and object-oriented programming issues; Experience in independent design, implementation, documentation and testing of application components; Very good and p ractical knowledge of Spring, Spring Boot, Hibernate/JPA and JEE frameworks; Practical knowledge with message queue systems, particularly RabbitMQ; Practical knowledge of tools supporting the software development process: Maven, Git, Gitlab, Gitlab CI/CD, Jenkins, Nexus, Jira; Knowledge of relational databases, in particular Oracle; Practical knowledge of RESTful API design; Experience in system integration; Experience with distributed systems; Experience with application servers, JBoss/WildFly; Knowledge of scannnfg tools (Fortify, Sonatype..) Description of the area of involvement TMS (Terminal Management System) is used to manage a very large number of payment terminals (300k+), it gives users a uniform way to manage different terminals from different hardware vendors. TMS has a complex architecture, consisting of two components TMS (1 WildFly instance) providing GUI and implementing some business functions and RTMS (3 Spring-boot instances) implementing most of the business functionalities. A gradual migration from TMS to RTMS is being carried out. The system intensively uses Spring, Hibernate and RabbitMQ. The system has distributed transactions (different two-phase-commit, saga approaches) and distributed cache (Hazelcast). TMS is integrated with many internal and external systems (via REST, SOAP, RMI, direct database connections and database links). The GUI is written in GWT and GWTExt. Hays Poland sp. z o.o. is an employment agency registered in a registry kept by Marshal of the Mazowieckie Voivodeship under the number 361

🏢 Summary: Senior Java Developer role focused on designing and enhancing a large-scale payment terminal management system in a hybrid Warsaw-based setup. The position involves building, integrating, and upgrading distributed solutions to improve performance, security, and scalability. You will work with legacy systems, automated testing, and message-driven architectures in a complex financial environment. 🗂️ Requirements: Minimum 4 years of Java development experience, Strong object-oriented programming skills, Proficiency in Java 8+, Experience with Spring and Spring Boot, Experience with Hibernate/JPA and JEE, Hands-on experience with RabbitMQ or other message queues, Experience with Maven and Git, Familiarity with Gitlab, Jenkins, Nexus, Jira, Strong knowledge of Oracle or other relational databases, Experience designing and integrating REST APIs, Experience with distributed systems, Experience with JBoss or WildFly, Experience with Hazelcast or other caching technologies, Good command of English (B2 level) 📃 Skills: Java, Spring, SpringBoot, Hibernate, JPA, JEE, RabbitMQ, Maven, Git, Gitlab, Jenkins, Nexus, Jira, Oracle, REST, JBoss, WildFly, Hazelcast, Docker, Kubernetes, Fortify, Sonatype, Microservices 🏢 Description: Ignite innovation in enterprise systems — architect the future of payment terminal management! Warszawa-based opportunity with hybrid work model. As a Senior Java Developer – Backend and System Integration , you will be working for our client, a leader in terminal management systems, focused on managing extensive payment terminals across diverse hardware vendors. You will help design and implement scalable IT solutions that enhance system integration and optimize business processes, contributing to cutting-edge financial technology. Your main responsibilities: Design and implement IT solutions based on analytical and technical documentation. Review and create technical documentation for system components. Perform system upgrades and work with legacy code, including reverse engineering. Define and build test cases for automated testing frameworks. Collaborate on system integration projects using REST, SOAP, RMI, and database links. Contribute to migration efforts from TMS to RTMS components. Work with distributed systems, message queues (RabbitMQ), and application servers (WildFly/JBoss). Support vulnerability assessments and ensure system security compliance. You're ideal for this role if you have: At least 4 years of experience in Java development and system integration. Very good knowledge of Java 8+ and object-oriented programming. Practical experience with Spring, Spring Boot, Hibernate/JPA, and JEE frameworks. Hands-on experience with RabbitMQ and relational databases, especially Oracle. Proficiency in RESTful API design and distributed systems. Familiarity with application servers (WildFly/JBoss) and version control (Git, Maven, Jenkins, GitLab CI/CD). It is a strong plus if you have: Experience with scanning tools like Fortify or Sonatype. Knowledge of Hazelcast for distributed caching. Language Required for the role: Fluent Polish and English, at least B2 level. Eligibility for the role: Only candidates with an existing legal right to work in the European Union 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 designing and modernizing distributed microservices systems for large-scale payment terminal management. The position involves building and optimizing secure, scalable solutions using Java and related enterprise technologies in a hybrid Warsaw-based model. 🗂️ Requirements: 4+ years of Java development experience, Strong knowledge of Java 8+ and OOP, Experience with Spring and Spring Boot, Experience with Hibernate/JPA and JEE, Practical experience with RabbitMQ, Experience with Maven and Git, Experience with CI/CD and Jenkins, Experience with relational databases (Oracle), Experience designing RESTful APIs, Experience with distributed systems, Knowledge of JBoss or WildFly, Ability to work from Warsaw office 4 days per week, Fluent Polish and English (B2), Legal right to work in the EU 📃 Skills: Java, Spring, SpringBoot, Hibernate, JPA, JEE, RabbitMQ, Maven, Git, Gitlab, CI/CD, Jenkins, Nexus, Jira, Oracle, REST, JBoss, WildFly 🏢 Description: Unleash innovation in distributed systems — shape the future of microservices! Warsaw-based opportunity with hybrid work model. As a Senior Java Developer , you will be working for our client, an industry leader in terminal management systems, dedicated to creating robust solutions for managing millions of payment terminals worldwide. You will contribute to the design and implementation of cutting-edge IT solutions that enhance system performance, security, and scalability, driving digital transformation in the payments industry. Your main responsibilities: Design and implement IT solutions based on analytical and technical documentation Review and validate analytical documentation to ensure system integrity Create detailed technical documentation for development and maintenance Perform technical upgrades and work with legacy codebases Conduct regular vulnerability scans to ensure system security Collaborate on distributed systems development utilizing Spring, Hibernate, and RabbitMQ Support system integration with internal and external APIs and services Optimize and maintain application servers such as JBoss/WildFly Contribute to the migration and modernization of existing systems You're ideal for this role if you have: 4+ years of experience in Java development, with senior-level expertise Strong knowledge of Java 8+ and object-oriented programming principles Proven experience with Spring, Spring Boot, Hibernate/JPA, and JEE frameworks Practical knowledge of message queue systems, particularly RabbitMQ Familiarity with tools supporting development processes: Maven, Git, Gitlab, CI/CD pipelines, Jenkins, Nexus, Jira Working experience with relational databases, especially Oracle Practical knowledge of RESTful API design Experience with distributed systems and system integration Knowledge of application servers, including JBoss/WildFly Ability to review analytical documentation and create technical specifications Excellent command of Polish and English (B2 level) Ability to work from the Warsaw office 4 days per week + 1 day remote It is a strong plus if you have: Experience with scanning tools such as Fortify or Sonatype Eligibility to work on this role: Only candidates with an existing legal right to work in the European Union 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 designing and modernizing distributed microservices systems for large-scale payment terminal management. The position involves building secure, scalable solutions using Java and related enterprise technologies, supporting system integration and legacy modernization. Hybrid work model in Warsaw with strong emphasis on system performance, security, and reliability. 🗂️ Requirements: 4+ years of Java development experience, Strong knowledge of Java 8+ and OOP, Experience with Spring and Spring Boot, Experience with Hibernate/JPA and JEE, Experience with RabbitMQ or message queues, Experience with RESTful APIs, Experience with relational databases (Oracle), Experience with distributed systems and system integration, Knowledge of JBoss or WildFly, Experience with Maven, Git, Gitlab, Jenkins, Nexus, Jira, Ability to create and review technical documentation, English level B2, Ability to work from Warsaw office 4 days per week, Legal right to work in the EU 📃 Skills: Java, Spring, SpringBoot, Hibernate, JPA, JEE, RabbitMQ, REST, Oracle, Maven, Git, Gitlab, Jenkins, Nexus, Jira, JBoss, WildFly, CICD, DistributedSystems 🏢 Description: Unleash innovation in distributed systems — shape the future of microservices! Warsaw-based opportunity with hybrid work model. As a Senior Java Developer , you will be working for our client, an industry leader in terminal management systems, dedicated to creating robust solutions for managing millions of payment terminals worldwide. You will contribute to the design and implementation of cutting-edge IT solutions that enhance system performance, security, and scalability, driving digital transformation in the payments industry. Your main responsibilities: Design and implement IT solutions based on analytical and technical documentation Review and validate analytical documentation to ensure system integrity Create detailed technical documentation for development and maintenance Perform technical upgrades and work with legacy codebases Conduct regular vulnerability scans to ensure system security Collaborate on distributed systems development utilizing Spring, Hibernate, and RabbitMQ Support system integration with internal and external APIs and services Optimize and maintain application servers such as JBoss/WildFly Contribute to the migration and modernization of existing systems You're ideal for this role if you have: 4+ years of experience in Java development, with senior-level expertise Strong knowledge of Java 8+ and object-oriented programming principles Proven experience with Spring, Spring Boot, Hibernate/JPA, and JEE frameworks Practical knowledge of message queue systems, particularly RabbitMQ Familiarity with tools supporting development processes: Maven, Git, Gitlab, CI/CD pipelines, Jenkins, Nexus, Jira Working experience with relational databases, especially Oracle Practical knowledge of RESTful API design Experience with distributed systems and system integration Knowledge of application servers, including JBoss/WildFly Ability to review analytical documentation and create technical specifications Excellent command of Polish and English (B2 level) Ability to work from the Warsaw office 4 days per week + 1 day remote It is a strong plus if you have: Experience with scanning tools such as Fortify or Sonatype Eligibility to work on this role: Only candidates with an existing legal right to work in the European Union 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: Development role focused on designing and implementing a Kubernetes Operator for a Red Hat MicroShift–based platform to enable automated mTLS for containerized applications. The position involves secure key management with TPM integration, Kubernetes networking, and Linux-level automation to deliver production-ready DevSecOps solutions. The role centers on building secure, hardware-backed communication mechanisms within embedded and edge environments. 🗂️ Requirements: 5+ years commercial experience in DevOps or DevSecOps, Strong knowledge of Kubernetes, including networking, Hands-on experience with Kubernetes Operators, Proficiency in Go or Rust (at least one as primary language), Solid Linux fundamentals and OS-level experience, Understanding of mTLS and certificate-based authentication, Fluency in English (minimum B2), Residence in Poland 📃 Skills: Kubernetes, Go, Rust, Linux, mTLS, TPM, PKI, MicroShift, Docker, Bash, Networking, Ingress, Egress, Certificates 🏢 Description: Join our engineering team to develop an APM operator for a Red Hat MicroShift–based platform. The operator will enable containerized applications to use mutual TLS (mTLS) for internet‑facing connectivity. You will work closely with the operating system and Kubernetes stack, designing an operator and an access layer for hardware security (TPM) to securely manage private keys. By joining us, you become a member of the Embedded Competence Center at Sii is an internal organizational unit bringing together more than 500 specialists nationwide! We are currently working on about 100 projects for 50 clients from various industries, including automotive, IoT, telecommunications, and medical. Your tasks Design and implement a Kubernetes Operator for a Red Hat MicroShift–based platform Enable and automate mTLS for containerized applications (internet‑facing connectivity) Implement and integrate secure key handling (TPM access layer / hardware‑backed keys when applicable) Work on Kubernetes networking aspects (services, ingress/egress, policies, certificates) Build and maintain Linux‑level components and automation/scripts supporting the platform Collaborate with platform/security stakeholders, document decisions, and deliver production‑ready code Requirements At least 5 years of commercial experience as a DevOps / DevSecOps Strong Kubernetes knowledge, including networking on Kubernetes Hands‑on experience with Kubernetes Operators Good command of Go and/or Rust – at least one as primary language Solid Linux fundamentals and experience working closely with the OS Understanding of mTLS / certificate‑based authentication and secure communications Fluency in English – at least B2 Residing in Poland required Nice-to-have requirements Knowledge of TPM / hardware security concepts (helpful, not mandatory) Previous work with Red Hat MicroShift or other edge/embedded Kubernetes distributions Experience with PKI, certificate lifecycle automation, or service mesh concepts 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!