Senior Java Developer

🏢 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 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 building and maintaining backend microservices in the Credit Data Sourcing domain within a banking environment. The position involves designing data flows, system integrations, and scalable business logic, as well as supporting production incidents. Work is performed in an Agile team with hybrid presence in Poland. 🗂️ Requirements: Strong experience with Java and backend development, Experience designing and maintaining microservices, Experience with data flows and data sourcing systems, Experience in integration-heavy environments, Ability to analyze end-to-end data flow across systems, Ability to assess impact on upstream and downstream systems, Experience working with distributed systems, Experience in incident analysis and troubleshooting, Understanding of financial or credit domain systems 📃 Skills: Java, Microservices, Dataflows, Integrations, Distributed, Banking, Credit, Agile, Scrum, Troubleshooting 🏢 Description: OFFER DETAILS: Industry: Banking Location: Warsaw / Gdańsk / Łódź Work model: Hybrid – 3 days per week in the office required Rate: up to 160 PLN/hour net + VAT Contract type: B2B Overview: The Senior Java Developer role focuses on the development and maintenance of backend services in the Credit Data Sourcing domain. This position requires strong involvement in data flows, integrations, and business logic, along with close collaboration with Business Analysts, Product Owners, and other stakeholders. The role also includes participating in production support and incident resolution. Main Responsibilities: Design, develop, and maintain Java-based microservices. Implement and optimize data flows and integrations between systems. Collaborate with analysts on user stories, acceptance criteria, and solution design. Translate business requirements into scalable technical solutions. Support incident analysis and troubleshooting including logs and root cause analysis. Contribute to refinement sessions and technical design discussions. Ensure high-quality code, testing, and performance. Key Requirements: Experience in data flows and data sourcing systems. Experience in integration-heavy environments. Ability to understand end-to-end data flow across systems. Ability to analyze impact of changes on upstream/downstream systems. Experience in the financial/credit domain is advantageous. Strong analytical and problem-solving skills. Good communication with both technical and business stakeholders. Ownership mindset and responsibility for delivery. Comfortable working in complex, distributed systems. Nice to Have: Experience with frontend frameworks like Angular or React. Experience in credit risk and banking systems. Experience with event-driven architectures. Performance tuning in data-heavy systems. Other Details: This position is based in Poland, specifically in Gdańsk, Warsaw, or Łódź. The role operates within an Agile/Scrum team environment, emphasizing close collaboration and regular alignment around releases. Ideal candidates will thrive in a dynamic, interdisciplinary setting.

🏢 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: Contract role for a Senior Java Backend Developer to design and build scalable backend systems and microservices for a large enterprise digital platform in a hybrid model in Poland. The position focuses on developing RESTful services, integrating external systems, and optimizing distributed applications. Requires strong experience in Java-based microservices architecture and modern DevOps tools. 🗂️ Requirements: 7+ years of Java development experience, Strong expertise in Java 8+, Experience with Spring and related frameworks, Hands-on microservices development, Experience with RESTful APIs and web services, Experience with Kafka or distributed messaging systems, Understanding of SOA principles, Experience with relational or NoSQL databases, Experience with containerization and orchestration, Knowledge of React or advanced JavaScript, Proficiency with Git, Maven, Jenkins, Registration in Poland as self-employed consultant 📃 Skills: Java, Spring, SpringBoot, SpringMVC, JPA, Hibernate, REST, SOAP, HTTP, JSON, XML, Kafka, SQL, NoSQL, Docker, Git, Maven, Jenkins, React, JavaScript 🏢 Description: Dear Consultant, We are seeking an experienced Senior Java Backend Developer to design and build scalable backend systems and microservices for a large enterprise digital platform. Send CV if you are interested and registered in Poland as a self-employed Consultant. (marcillina.tietjen@dcvtechnologies.co.uk) Senior Java Backend Developer – Microservices (Contract) Location: Gdansk or Warsaw, Poland Work Mode: Hybrid – 1 day onsite per week Seniority: 7+ years experience Key Responsibilities • Design and implement backend systems and microservices• Develop RESTful APIs and web services• Participate in architecture reviews and optimisation initiatives• Debug, profile, and optimise applications• Integrate external APIs and services• Write and maintain technical documentation Required Skills & Experience • Strong expertise in Java 8+ • Frameworks: Spring, Spring Boot, Spring MVC, JPA, Hibernate • Microservices development using HTTP, REST, JSON, XML • Messaging and distributed systems experience ( Kafka ) • Strong understanding of SOA principles and web services (REST & SOAP) • Experience with Relational or NoSQL databases • Exposure to containerisation & orchestration technologies • Experience with React or advanced JavaScript • Tools: Docker, Git, Maven, Jenkins

🏢 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, 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 building and maintaining Java-based microservices, APIs, and data integration solutions in a hybrid B2B setup. The position involves ETL processes, database operations, and collaboration in a DevOps-driven environment. Experience with Java, Spring Boot, Kafka, PostgreSQL, and cloud-native tools is required. 🗂️ Requirements: 8+ years of software development experience, Java, Spring Boot, Microservices architecture, API development, Kafka, PostgreSQL, SQL, DataStage, Kubernetes, Jenkins, Bitbucket, DevOps experience, Fluent English 📃 Skills: Java, Spring, Kafka, PostgreSQL, SQL, DataStage, Kubernetes, Jenkins, Bitbucket, Microservices, APIs, ETL, DevOps 🏢 Description: Senior Java Developer Location: Hybrid (2 days/week from Warsaw, Gdańsk, Gdynia, or Łódź) Contract: B2B via Experis Start Date: ASAP / up to 30 days notice period Responsibilities Develop and maintain data integration solutions and data flow processes Build and enhance Java-based microservices and APIs Support ETL processes and database operations Collaborate in a DevOps-driven environment Requirements 8+ years of experience in software development Strong experience with Java and Spring Boot Experience with microservices architecture and APIs Knowledge of Kafka Experience with PostgreSQL and SQL Knowledge of DataStage (ETL) Familiarity with Kubernetes, Jenkins, and Bitbucket DevOps mindset Strong communication and teamwork skills Fluent English Nice to Have Experience in the banking or financial industry Benefits Medicover healthcare Multisport card Group life insurance Access to e-learning platform

🏢 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: Long-term B2B contract for a Senior Java Developer to design, build and maintain backend applications and microservices using Spring Boot, with strong focus on system architecture, integrations and cloud environments. The role involves developing REST and asynchronous communication, working with SQL databases, containerization and CI/CD pipelines. Fully remote or hybrid work model available. 🗂️ Requirements: Commercial experience in backend development with Java 11+, Strong knowledge of Java and Spring Framework, Experience in designing and developing microservices, Experience with REST API and asynchronous communication (Kafka, MQ), Practical knowledge of SQL databases (Oracle or PostgreSQL), Experience with Git and CI/CD pipelines, Experience with Docker and Kubernetes, Experience working in Linux environments, Experience with cloud platforms, Ability to write unit and integration tests, Experience working in Agile/Scrum, English proficiency for technical communication 📃 Skills: Java, Spring, SpringBoot, REST, Kafka, MQ, Oracle, PostgreSQL, SQL, Git, CI/CD, Docker, Kubernetes, Linux, Cloud, HTTP, JSON 🏢 Description: Senior Java Developer poszukiwany(-a)! Lokalizacja: 100% zdalnie / hybrydowo (Warszawa/Wrocław/Kraków - do ustalenia) Forma współpracy: B2B Wynagrodzenie (B2B): do 160 zł/h netto + VAT Start: do uzgodnienia Czas trwania projektu: długofalowa współpraca Obowiązki Projektowanie, rozwój i utrzymanie aplikacji backendowych w Javie z wykorzystaniem Spring Framework / Spring Boot Projektowanie i implementacja mikroserwisów oraz komunikacji pomiędzy nimi (REST, integracje asynchroniczne) Tworzenie i utrzymanie szablonów mikroserwisów, bibliotek oraz komponentów platformowych Integracja systemów z wykorzystaniem narzędzi kolejkowych ( Kafka, MQ ) Praca z bazami danych ( Oracle, PostgreSQL ) Udział w projektowaniu architektury systemów oraz doborze technologii Wdrażanie i utrzymanie rozwiązań w różnych środowiskach chmurowych Pisanie testów jednostkowych i integracyjnych , przeprowadzanie code review Monitorowanie i optymalizacja wydajności systemów Tworzenie i promowanie standardów technicznych oraz dobrych praktyk Wsparcie zespołów produktowych (mentoring, przeglądy kodu) Współpraca z zespołami frontend, QA, DevOps Praca w metodyce Agile Wymagania Komercyjne doświadczenie w tworzeniu aplikacji backendowych w Javie (Java 11+) Bardzo dobra znajomość Java oraz Spring Framework / Spring Boot Doświadczenie w projektowaniu i rozwoju mikroserwisów Znajomość REST API , HTTP/JSON oraz komunikacji asynchronicznej ( Kafka, MQ ) Praktyczna znajomość baz danych SQL (np. Oracle, PostgreSQL), mile widziane NoSQL Doświadczenie z Git , CI/CD oraz narzędziami developerskimi Znajomość Docker i Kubernetes oraz pracy w środowisku Linux Doświadczenie w pracy z platformami chmurowymi Umiejętność tworzenia wydajnych i jakościowych rozwiązań , dbałość o standardy kodu Doświadczenie w pracy w metodykach Agile / Scrum Samodzielność, dobra organizacja pracy i umiejętności komunikacyjne Znajomość języka angielskiego na poziomie umożliwiającym swobodną komunikację Mile widziane: doświadczenie z technologiami front-end, np. Angular, React Nie zwlekaj i zaaplikuj już teraz! Nr ref.: 58/12/2025/MB/2997