Senior Java Developer

🏢 Summary: Senior backend engineering role focused on building and maintaining high-volume travel and transactional systems using Java microservices architecture. The position involves developing REST and gRPC services, deploying cloud-native solutions on GCP and Kubernetes, and supporting booking, ticketing, pricing, and integration workflows. The role also includes CI/CD participation, production support, troubleshooting, and mentoring junior developers. 🗂️ Requirements: 8+ years of experience with Java, Experience with Spring Boot, Experience building microservices, Experience developing REST APIs, Experience developing gRPC services, Hands-on experience with GCP, Hands-on experience with Docker, Hands-on experience with Kubernetes, Knowledge of GitHub, Knowledge of Jenkins or GitHub Actions, Familiarity with Prometheus, Familiarity with Stackdriver or Cloud Monitoring, Basic scripting skills in Python or Bash, Experience with WireMock, Experience with performance testing, Legal work permit in Poland 📃 Skills: Java, Spring, SpringBoot, Microservices, REST, gRPC, GCP, Docker, Kubernetes, GitHub, Jenkins, GitHubActions, Prometheus, Stackdriver, CloudMonitoring, Python, Bash, WireMock 🏢 Description: A largescale, highly complex initiative focused on the development and maintenance of core internal systems. The project ensures seamless communication and integration between various backend components responsible for critical, high-volume travel and transactional operations. Quick Facts - System Integration: Facilitating robust and efficient communication between internal microservices and proprietary component. - Booking & Ticketing Lifecycle: Supporting core transactional flows, including ticket reservations, refunds, and exchanges. - Search & Optimization: Powering backend algorithms designed to find and generate the most optimal flight connections. - Financial Calculations: Handling complex pricing engines, fare structures, and diverse cost-assessment calculations. Responsibilities - Design, develop, test and maintain backend applications using Java and Spring Boot. - Build and support RESTful APIs and gRPC services. - Develop solutions deployed on Google Cloud Platform (GCP) and Kubernetes. - Collaborate with QA, SRE, and Product teams. - Participate in CI/CD processes, deployments, and production support. - Provide support during release cycles, including smoke testing and manual validation. - Troubleshoot issues using logs, metrics, and monitoring tools. - Conduct code reviews, mentor junior developers, and participate in an on-call rotation. Requirements - 8+ years of experience with Java and Spring Boot. - Experience building microservices, REST APIs, and gRPC services. - Hands-on experience with GCP, Docker, and Kubernetes. - Knowledge of GitHub, Jenkins, or GitHub Actions. - Familiarity with monitoring tools such as Prometheus and Stackdriver/Cloud Monitoring. - Basic scripting skills in Python or Bash. - Experience with WireMock and performance testing. - Must possess a legal work permit in Poland. Benefits - General benefits depending on the form of employment. - Hybrid work model combining office and remote work. - Attractively located office with collaboration spaces. - Onsite parking space for employees. - Referral program with financial bonus. - Life insurance. - Budget for development including language courses and other learning opportunities. - Clear career path with the possibility to gain experience in an international environment. - Access to an internal learning platform with multiple trainings oriented for professional growth. - Access to MyBenefit platform (Multisport included). - Team building activities. - Charity initiatives. - Working environment promoting diversity and inclusion. - Private medical care – Platinum Package.

🏢 Summary: Senior Java Developer role focused on designing, building, and maintaining scalable, secure, high-performance backend systems using modern Java and cloud-native technologies. The position involves working in Agile teams, leading technical discussions, mentoring developers, and driving DevOps automation. Hybrid work model with regular presence in the Warsaw office. 🗂️ Requirements: 8+ years of backend development experience, Proficiency in Java 17+, Experience with Spring Boot and Spring Security, Strong knowledge of Hibernate and JPA, Experience with Maven, Strong SQL skills with PostgreSQL, Experience in cloud-native application development, Hands-on experience with Git and GitHub pipelines, Experience with CI/CD tools, Experience with Kubernetes and Helm, Ability to write Bash/Shell scripts, Experience with JUnit, AssertJ, and Hamcrest, Degree in Computer Science or equivalent experience 📃 Skills: Java, Spring, SpringSecurity, Hibernate, JPA, Maven, PostgreSQL, SQL, Kubernetes, Helm, Docker, Bash, Git, GitHub, CICD, JUnit, AssertJ, Hamcrest 🏢 Description: Role Overview As a Senior Java Developer, you will design, build, and maintain scalable, secure, and high-performance backend systems. Working closely with cross-functional teams, you’ll drive innovation – including the use of GenAI tools like GitHub Copilot -and mentor other developers. Work mode: hybrid 2-3 days / 5 days at the Warsaw office. Key Responsibilities Backend & DB: Develop robust, multi-tenant applications using Java 17+, Spring Boot, and PostgreSQL. DevOps & Automation: Manage deployments using Docker, Kubernetes, and Helm; automate tasks via Bash/Shell scripting. Leadership & Agile: Lead design discussions, mentor peers, and actively participate in Scrum events within a distributed team. Requirements Technical Skills: Java Stack: Java 17+, Spring (Boot, Security), Hibernate/JPA, Maven. Data & Cloud: SQL (PostgreSQL), cloud-native application development. DevOps & CI/CD: Git/GitHub (pipelines), CI/CD tools, Kubernetes, Helm, Bash. Testing: JUnit, AssertJ, Hamcrest. Skills & Experience: 8+ years of professional backend experience (preferably in enterprise environments). Degree in Computer Science (or equivalent experience). Fluent English ( B2/C1 ) and strong collaboration skills in Agile teams. Nice-to-Have Kafka & Event-driven / Microservices architecture. Python, C, or Go (Golang) scripting. Monitoring tools (Kibana, Grafana, Prometheus). Security best practices (OWASP Top 10) & Jira. 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 Java Developer role focused on designing and owning the end-to-end architecture of a high-throughput, multitenant messaging platform in the travel industry. The position involves building event-driven microservices that generate traveler documents and deliver time-critical notifications via email and SMS at million-scale volumes. The role includes driving modernization, resilience, observability, and cloud-based scalability of the platform. 🗂️ Requirements: Expertise in Java and JVM performance, Experience designing large-scale event-driven systems, Hands-on experience with Spring Boot microservices, Experience with asynchronous messaging and API design, Experience with SQL and NoSQL databases and caching, Experience with Google GCP, Experience with high availability and disaster recovery architectures, Knowledge of email and SMS ecosystems and deliverability, Understanding of security and compliance standards (PII, GDPR, CAN-SPAM), Experience with static code analysis tools, Legal work permit in Poland 📃 Skills: Java, JVM, Spring, SpringBoot, SQL, NoSQL, GCP, OpenTelemetry, GitHubActions, Kubernetes, MTA, SPF, DKIM, DMARC, Veracode, CI, API, SMS, Email 🏢 Description: We are looking for a Senior Java Developer for our client, based in Kraków and surrounding areas. The project involves developing a large-scale communication platform in the travel industry that generates traveler documents and delivers time-critical notifications via email and SMS (over 1 million emails and approximately 100,000 SMS messages daily). The system is responsible for informing travelers about schedule changes, web check-in availability, and flight status (from 24 hours before departure up to the departure time), as well as collecting post-trip feedback. Own the end-to-end technical architecture for a multitenant, high throughput messaging platform: event driven services, template rendering, document generation, deliverability, and channel expansion Define service boundaries, data contracts, and platform SLOs (latency, throughput, deliverability); codify resilience (idempotency, retries, backoff, circuit breaking) and correctness (deduplication, exactly once where feasible). Lead design reviews and drive architectural RFCs/decision records; ensure documentation quality aligns with org guidelines. Guide modernization (e.g., Java 21 and newer, security hardening, SDLC improvements like GitHub Actions CI). Partner with Product to translate roadmap themes into platform epics (capacity, compliance, channel enablement); sequence tech debt with product outcomes. Elevate engineering standards, performance tuning, and observability (OpenTelemetry, metrics, logs, tracing). Collaborate with deliverability/infra teams on MTA configuration, SPF/DKIM/DMARC alignment, and reporting pipelines for at scale sending. Deep expertise in Java and JVM performance; significant experience designing event driven systems at millions per day scale. Handson Spring Boot microservices, asynchronous messaging, API design, and data stores (SQL/NoSQL, caching), Google GCP experience. Proven track record with HA, disaster recovery, multiregional patterns, and observability first design. Knowledge of email/SMS ecosystems (MTA, deliverability, anti abuse, link tracking, templating, internationalization). Security and compliance awareness (PII, GDPR, CAN-SPAM), static analysis workflows (e.g., Veracode). Ability to influence across product/engineering; excellent written design documentation. Nice to have Experience enabling new channels (RCS/WhatsApp), running canary/feature flags, and cost/perf optimization on cloud Kubernetes. Must possess a legal work permit in Poland General benefits - depends on the form of employment Hybrid work model combining office & remote work Attractively located office with collaboration spaces Onsite parking space for employees Referral program with financial bonus Life Insurance Budget for development (including language courses and others), clear career path with the possibility to gain experience in international environment Access to internal Learning Platform with multiple trainings oriented for professional growth Lifestyle benefits: Access to MyBenefit platform (Multisport included) Team Building activities Charity initiatives Working environment promoting diversity and inclusion Health benefits: Private medical care - Platinum Package

🏢 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!

🏢 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 Java Developer role focused on designing, building, and operating scalable fintech backend systems using Java and Spring Boot in cloud environments. The position involves developing high-performance microservices and APIs for payment, trading, and settlement platforms, with end-to-end ownership from architecture to production support. The role requires close collaboration with international teams and ensuring reliability, consistency, and fault tolerance in distributed systems. 🗂️ Requirements: 3–5 years backend development experience, Strong experience with Java, Strong experience with Spring Boot, Experience building scalable backend services and APIs, Knowledge of SQL and NoSQL databases, Understanding of microservices architecture, Understanding of distributed systems, Experience with asynchronous processing, Experience across full SDLC, Experience with AWS or Azure, Professional English proficiency 📃 Skills: Java, SpringBoot, Microservices, SQL, NoSQL, PostgreSQL, MySQL, MongoDB, AWS, Azure, REST, APIs, SDLC, DistributedSystems, AsynchronousProcessing 🏢 Description: Senior Java Developer (Java, Spring Boot, Microservices) Position Overview We are looking for a Senior Java Developer to join our team in Poland and contribute to the development of highly scalable fintech systems supporting trillions of dollars in transactions annually . In this role, you will work closely with the US-based product and engineering teams , helping to design, build, and operate backend services for programmable payment, trading, and settlement platforms. You will report directly to the Software Manager in Poland. A key requirement is excellent English communication skills and strong soft skills — we are looking for someone eloquent, outgoing, friendly, and confident in collaboration . Responsibilities Design and develop backend architecture for fintech products and platforms. Build, maintain, and operate high-performance Java / Spring Boot microservices running in production environments. Develop scalable APIs and backend workflows with strong emphasis on data consistency, fault tolerance, and reliability . Own features end-to-end: from implementation through deployment and production support. Debug and resolve complex issues in distributed systems and high-volume production environments. Work closely with US-based teams to translate product requirements into robust backend solutions. Write clean, maintainable code and contribute to technical documentation, diagrams, and system workflows. Participate in code reviews and continuously improve backend quality and engineering standards. Requirements 3–5 years of professional backend development experience. Strong hands-on experience with Java and Spring Boot in production systems. Proven experience building and maintaining backend services and APIs at scale. Solid understanding of SQL and NoSQL databases (e.g., PostgreSQL/MySQL, MongoDB). Knowledge of microservices architecture, distributed systems, and asynchronous processing. Experience across full SDLC: architecture, development, testing, deployment, and maintenance. Experience operating systems in cloud environments such as AWS or Azure . Excellent communication skills in English . Nice to Have Experience with Spring AI . Previous exposure to banking, payments, trading, or financial transaction systems. Degree in Computer Science or equivalent practical experience. Personal Attributes Highly hands-on engineer who enjoys owning production-grade code. Comfortable working in a fast-paced, startup or high-growth environment. Strong analytical thinking, problem-solving ability, and attention to detail. Clear communicator, confident in collaborating with international teams. Friendly, proactive, and motivated to grow with the company and product.

🏢 Summary: Senior Java Developer role focused on designing, building, and operating scalable fintech backend systems handling high-volume transactions. The position involves developing Java/Spring Boot microservices, scalable APIs, and distributed architectures in cloud environments. You will collaborate with international teams to deliver reliable, production-grade financial platforms. 🗂️ Requirements: 3–5 years of backend development experience, Strong experience with Java and Spring Boot in production, Experience building scalable backend services and APIs, Strong knowledge of SQL and NoSQL databases, Understanding of microservices architecture and distributed systems, Experience with asynchronous processing, Experience across full SDLC, Experience with AWS or Azure cloud environments, Professional English communication skills 📃 Skills: Java, Spring, SpringBoot, Microservices, SQL, NoSQL, PostgreSQL, MySQL, MongoDB, AWS, Azure, REST, APIs 🏢 Description: Senior Java Developer (Java, Spring Boot, Microservices) Position Overview We are looking for a Senior Java Developer to join our team in Poland and contribute to the development of highly scalable fintech systems supporting trillions of dollars in transactions annually . In this role, you will work closely with the US-based product and engineering teams , helping to design, build, and operate backend services for programmable payment, trading, and settlement platforms. You will report directly to the Software Manager in Poland. A key requirement is excellent English communication skills and strong soft skills — we are looking for someone eloquent, outgoing, friendly, and confident in collaboration . Responsibilities Design and develop backend architecture for fintech products and platforms. Build, maintain, and operate high-performance Java / Spring Boot microservices running in production environments. Develop scalable APIs and backend workflows with strong emphasis on data consistency, fault tolerance, and reliability . Own features end-to-end: from implementation through deployment and production support. Debug and resolve complex issues in distributed systems and high-volume production environments. Work closely with US-based teams to translate product requirements into robust backend solutions. Write clean, maintainable code and contribute to technical documentation, diagrams, and system workflows. Participate in code reviews and continuously improve backend quality and engineering standards. Requirements 3–5 years of professional backend development experience. Strong hands-on experience with Java and Spring Boot in production systems. Proven experience building and maintaining backend services and APIs at scale. Solid understanding of SQL and NoSQL databases (e.g., PostgreSQL/MySQL, MongoDB). Knowledge of microservices architecture, distributed systems, and asynchronous processing. Experience across full SDLC: architecture, development, testing, deployment, and maintenance. Experience operating systems in cloud environments such as AWS or Azure . Excellent communication skills in English . Nice to Have Experience with Spring AI . Previous exposure to banking, payments, trading, or financial transaction systems. Degree in Computer Science or equivalent practical experience. Personal Attributes Highly hands-on engineer who enjoys owning production-grade code. Comfortable working in a fast-paced, startup or high-growth environment. Strong analytical thinking, problem-solving ability, and attention to detail. Clear communicator, confident in collaborating with international teams. Friendly, proactive, and motivated to grow with the company and product.

🏢 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, building, and operating highly scalable fintech backend systems supporting high-volume payment, trading, and settlement platforms. The position involves developing production-grade Java/Spring Boot microservices, scalable APIs, and distributed systems in cloud environments. The engineer owns features end-to-end, ensuring reliability, fault tolerance, and performance in high-traffic financial systems. 🗂️ Requirements: 5–15 years backend development experience, Strong Java experience in production, Hands-on Spring Boot experience, Experience in fintech, banking, payments, or trading systems, Experience building scalable backend services and APIs, Strong SQL knowledge, Experience with NoSQL databases, Knowledge of microservices architecture, Understanding of distributed systems, Experience with asynchronous processing, Experience across full SDLC, Cloud experience with AWS or Azure, Experience debugging distributed systems, English communication skills 📃 Skills: Java, Spring, SpringBoot, SQL, PostgreSQL, MySQL, MongoDB, NoSQL, Microservices, DistributedSystems, AWS, Azure, REST, APIs, SDLC, AsynchronousProcessing 🏢 Description: We are looking for a Senior Java Developer to join our team in Poland and contribute to the development of highly scalable fintech systems supporting trillions of dollars in transactions annually . In this role, you will work closely with the US-based product and engineering teams , helping to design, build, and operate backend services for programmable payment, trading, and settlement platforms. You will report directly to the Software Manager in Poland. A key requirement is excellent English communication skills and strong soft skills — we are looking for someone eloquent, outgoing, friendly, and confident in collaboration . Requirements 5 -15 years of professional backend development experience. Strong hands-on experience with Java and Spring Boot in production systems. Previous exposure to banking, payments, trading, or financial transaction systems. Proven experience building and maintaining backend services and APIs at scale. Solid understanding of SQL and NoSQL databases (e.g., PostgreSQL/MySQL, MongoDB). Knowledge of microservices architecture, distributed systems, and asynchronous processing. Experience across full SDLC: architecture, development, testing, deployment, and maintenance. Experience operating systems in cloud environments such as AWS or Azure . Excellent communication skills in English . Nice to Have Experience with Spring AI . Degree in Computer Science or equivalent practical experience. Personal Attributes Highly hands-on engineer who enjoys owning production-grade code. Comfortable working in a fast-paced, startup or high-growth environment. Strong analytical thinking, problem-solving ability, and attention to detail. Clear communicator, confident in collaborating with international teams. Friendly, proactive, and motivated to grow with the company and product. Design and develop backend architecture for fintech products and platforms. Build, maintain, and operate high-performance Java / Spring Boot microservices running in production environments. Develop scalable APIs and backend workflows with strong emphasis on data consistency, fault tolerance, and reliability. Own features end-to-end: from implementation through deployment and production support. Debug and resolve complex issues in distributed systems and high-volume production environments. Work closely with US-based teams to translate product requirements into robust backend solutions. Write clean, maintainable code and contribute to technical documentation, diagrams, and system workflows. Participate in code reviews and continuously improve backend quality and engineering standards.

🏢 Summary: Senior Java Developer role focused on designing, implementing, and maintaining scalable and secure solutions within a complex payment terminal ecosystem. The position involves working with distributed systems, message queues, and legacy code while enhancing system performance and reliability. The role requires strong backend expertise and collaboration on integration and automated testing initiatives. 🗂️ 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 or JPA, Experience with JEE, Practical experience with RabbitMQ or other message queues, Experience with Maven, Git, Gitlab, Jenkins, Nexus, Jira, Strong knowledge of Oracle or other relational databases, Experience in RESTful API design and system integration, Experience with distributed systems, Experience with JBoss or WildFly, Experience with Hazelcast or cache technologies, Ability to create and maintain automated tests, Good command of English (B2 level), Legal right to work in the European Union 📃 Skills: Java, Spring, SpringBoot, Hibernate, JPA, JEE, RabbitMQ, Maven, Git, Gitlab, Jenkins, Nexus, Jira, Oracle, SQL, REST, JBoss, WildFly, Hazelcast 🏢 Description: Warsaw-based opportunity with hybrid work model (4 days from the office / week) As a Senior Java Developer , you will be working for our client, a leader in managing a complex payment terminal ecosystem that connects thousands of devices across multiple vendors. You will play a pivotal role in designing and implementing cutting-edge IT solutions to enhance the system’s performance, security, and scalability, driving the future of financial transactions. Your main responsibilities: Design and implement IT solutions based on analytical and technical documentation Review analytical documentation and create comprehensive technical documentation Conduct technical upgrades and work with legacy code to maintain system integrity Perform reverse engineering using existing source code and documented business processes Define and build test cases for automated testing frameworks Collaborate on system integration tasks involving distributed systems and message queues Support ongoing system improvements and security assessments, including vulnerability scans You're ideal for this role if you have: At least 4 years of experience in Java development, with strong object-oriented programming skills In-depth knowledge of Java 8+ and frameworks such as Spring, Spring Boot, Hibernate/JPA, and JEE Practical experience with message queue systems, especially RabbitMQ Familiarity with tools like Maven, Git, Gitlab, Jenkins, Nexus, and Jira supporting software development Solid understanding of relational databases, particularly Oracle Hands-on experience with RESTful API design and system integration Experience working with distributed systems, application servers (JBoss/WildFly), and cache technologies (Hazelcast) Knowledge of security scanning tools like Fortify or Sonatype is a plus Good command of English (B2 level) and excellent communication skills It is a strong plus if you have: Additional certifications in Java or cloud technologies Experience with microservices architecture and containerization (e.g., Docker, Kubernetes) Language Required for the role: Good command of English (Communicative level) Eligibility for the role: Only candidates with an existing legal right to work in the European Union will be considered for this role. We offer you: ITDS Business Consultants is involved in various, innovative, and professional IT projects for international companies in the financial industry in Europe. We offer an environment for professional, ambitious, and driven people. The offer includes: Stable and long-term cooperation with very good conditions Enhance your skills and develop your expertise in the financial industry Work on the most strategic projects available in the market Define your career roadmap and develop yourself in the best and fastest possible way by delivering strategic projects for different clients of ITDS over several years Participation in Social Events, training, and work in an international environment Access to an attractive Medical Package Access to Multisport Program #GETREADY Internal job ID #9111 You can report violations in accordance with ITDS’s Whistleblower Procedure available here . #MAKEYourCareerBETTER