Senior Java Developer - Backend Engineering Team

🏢 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 Tech Lead Java consulting role focused on designing and leading scalable backend development for gaming and digital platform services in a hybrid Lisbon setup with occasional travel to the UK. The position combines hands-on Java engineering, architecture ownership, team leadership, and collaboration across distributed international teams. 🗂️ Requirements: 8+ years of Backend Java development experience, Strong expertise in Java, Strong expertise in Spring, Strong expertise in Spring Boot, Strong expertise in Hibernate, Strong expertise in JPA, Experience with REST APIs, Experience with Oracle databases, Experience with MySQL databases, Experience designing scalable backend systems, Experience with CI/CD tools, Experience with Git, Previous technical leadership or senior developer experience, Knowledge of software architecture and design patterns, Fluent English, Ability to work in hybrid model in Lisbon, Availability for periodic travel to the UK 📃 Skills: Java, Spring, SpringBoot, Hibernate, JPA, REST, SQL, Oracle, MySQL, Git, Jenkins, Azure, AWS, Scala, Docker, Kubernetes, Scrum 🏢 Description: Location: Lisbon Model: Hybrid - 2 times a week at Lisbon’s office | Availability for monthly travel to Watford Duration: 12+ months Languages: English (mandatory) Engagement: Full-time consulting Seniority: Tech Lead / Senior Java Engineer Industry: Gaming / Lottery / Digital Platforms About the Role We are seeking an experienced Tech Lead – Java to join our engineering team. This role requires a strong technical leader capable of driving architectural decisions, mentoring developers, ensuring code quality, and contributing hands-on to backend development using modern Java frameworks. The Tech Lead will collaborate with Product Owners, Architects, Senior Developers, and QA teams to design, build, and maintain highly scalable and reliable backend services. Main Responsibilities Technical Leadership Lead and mentor a team of Java developers across multiple workstreams. Provide technical guidance, code review, and best-practice enforcement (coding standards, testing, architecture). Coordinate with solution architects to ensure alignment on system design. Drive technical decision-making and ensure platform scalability and maintainability. Software Design & Development Lead the design of backend components in Java , Spring , Spring Boot , Hibernate/JPA . Develop new modules, APIs, and integrations in a large-scale distributed environment. Ensure the implementation of robust and efficient solutions aligned with business needs. Maintain and improve existing features, ensuring optimal performance. Architecture & Integration Translate functional requirements into technical specifications. Oversee integration with Oracle and MySQL databases. Design RESTful services following best security and performance practices. Ensure compatibility with frontend, middleware, and third-party services. Quality & Delivery Ensure high quality through automated tests, CI/CD, and code reviews. Collaborate with QA to guarantee full traceability of requirements → features → test cases. Use Azure DevOps for backlog management, pipelines, and documentation. Cross-Team Collaboration Act as the bridge between engineering, product, QA, and business teams. Contribute to sprint planning, backlog refinement, and architectural discussions. Coordinate with internal engineering teams distributed globally. Key Requirements Core Technical Skills 8+ years of professional experience in Backend Java Development . Strong expertise in: Java (8+) Spring & Spring Boot Hibernate / JPA REST APIs SQL databases (Oracle, MySQL) Solid experience designing scalable backend systems. Familiarity with CI/CD tools and version control (Git, Jenkins, etc.). Experience with cloud environments (Azure or AWS) is a plus. Technical Leadership Previous experience leading small teams or acting as senior reference developer. Strong knowledge of software architecture, patterns, and best practices. Ability to guide developers through complex debugging and architectural challenges. Soft Skills Strong communication skills and ability to work with cross-functional teams. Ownership mindset with a proactive approach. Fluent in English (mandatory). Ability to collaborate in an international environment. Nice to Have Knowledge of Scala or other JVM languages. Experience with containerization (Docker, Kubernetes). Familiarity with gaming or high-transaction environments. Exposure to Agile methodologies (Scrum). Other Details This is a hybrid role based in Lisbon with a requirement for remote collaboration and availability for periodic travel to the UK.

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

🏢 Summary: Senior Backend Engineer role focused on designing and developing scalable, reliable backend services using Java. The position involves working in a cross-functional team to build high-performance systems, improve architecture, and support CI/CD and production environments. 🗂️ Requirements: 5+ years Backend Engineering experience, Strong Java proficiency, Solid knowledge of databases and SQL, Experience with RESTful APIs, Experience with microservices architecture, Experience with high-load systems, Experience with Docker and Kubernetes, Experience with AWS or GCP, Knowledge of CI/CD pipelines, Understanding of Agile practices 📃 Skills: Java, SQL, REST, Microservices, Docker, Kubernetes, AWS, GCP, CI/CD, Golang, Python 🏢 Description: We are looking for a Senior Backend Engineer with strong Java experience to help us design and develop scalable solutions. You will work in a cross-functional team, building reliable services and contributing to the continuous improvement of our systems. This role is ideal for someone who enjoys solving complex problems and driving technical excellence. 💼 Responsibilities: Design, develop, and maintain backend features and services. Collaborate with teams to define requirements and integrate systems. Ensure performance, scalability, and reliability of applications. Contribute to CI/CD processes and support production systems. Write clear documentation and share knowledge within the team. ✅ Requirements: 5+ years of experience as a Backend Engineer, with strong Java skills (Golang/Python is a plus). Solid understanding of databases and SQL. Experience with RESTful API design, microservices, and high-load systems. Familiarity with Docker, Kubernetes, and cloud environments (AWS/GCP). Knowledge of CI/CD pipelines and Agile practices. Strong problem-solving and communication skills. 🎁 We offer: Stable employment in a fast-growing company. Flexible and remote-friendly working model. Health and wellbeing benefits. Learning and development opportunities. Modern equipment and comfortable work environment.

🏢 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: Backend Java Engineer role focused on developing and modernizing a high-load B2B gaming back-office platform processing millions of real-time transactions daily. The position involves building new features, improving scalability and reliability, and evolving a monolithic system toward distributed services. You will contribute to architectural design, performance optimization, and production issue resolution. 🗂️ Requirements: 5+ years of Java development experience, Strong knowledge of backend architecture, Experience with distributed systems, Experience with relational databases and SQL, Experience with message-driven systems, Experience refactoring production systems, Strong debugging and problem-solving skills, Intermediate English or higher 📃 Skills: Java, Spring, MSSQL, SQL, Kafka, Redis, Microservices 🏢 Description: Role Overview: We are looking for an experienced Java Engineer to join the client's backend team, which is working on the back-office platform of a high-load B2B gaming system. Their platform processes millions of transactions daily and supports real-time operations for multiple partners. As the system continues to grow, the engineering team is expanding to improve scalability, performance, and reliability, while gradually evolving parts of the platform from a monolithic architecture toward distributed services. You will work on both new functionality and architectural improvements, helping modernise critical parts of the platform. Technology Stack: Java 8 / Java 17, Spring Framework, MSSQL 2019, Kafka, Redis, distributed services with parts of the system still evolving from a monolithic architecture. Key Responsibilities: Develop new backend functionality for the platform; Improve system performance, scalability, and reliability; Participate in refactoring and modernisation of legacy components; Contribute to architectural discussions and technical design; Investigate and resolve production issues; Assess technical feasibility and complexity of business requirements; Collaborate closely with backend engineers, technical leads, and product teams Required Skills & Experience: 5+ years of Java development experience; Strong understanding of backend architecture and distributed systems; Experience working with relational databases and SQL; Familiarity with message-driven systems (Kafka or similar); Experience in improving or refactoring existing production systems; Strong problem-solving and debugging skills; Comfortable working in collaborative environments with code reviews and shared ownership of the codebase; English level: Intermediate or higher. The company guarantees you the following benefits: Global Collaboration: Join an international team where everyone treats each other with respect and moves towards the same goal; Autonomy and Responsibility: Enjoy the freedom and responsibility to make decisions without the need for constant supervision; Competitive Compensation: Receive competitive salaries reflective of your expertise and knowledge as our partner seeks top performers; Remote Work Opportunities: Embrace the flexibility of fully remote work, with the option to visit company offices that align with your current location; Flexible Work Schedule: Focus on performance, not hours, with a flexible work schedule that promotes a results-oriented approach; Unlimited Paid Time Off: Prioritise work-life balance with unlimited paid vacation and sick leave days to prevent burnout; Career Development: Access continuous learning and career development opportunities to enhance your professional growth; Corporate Culture: Experience a vibrant corporate atmosphere with exciting parties and team-building events throughout the year; Referral Bonuses: Refer talented friends and receive a bonus after they successfully complete their probation period; Medical Insurance Support: Choose the right private medical insurance and receive compensation (full or partial) based on the cost; Flexible Benefits: Customise your compensation by selecting activities or expenses you'd like the company to cover, such as a gym subscription, language courses, Netflix subscription, spa days, and more; Education Foundation: Participate in a biannual raffle for a chance to learn something new unrelated to your job as part of your commitment to ongoing education. Interview process: HR Interview with the Recruiter; Technical interview with the team; A 2-hour Final interview with the team. If you find this opportunity right for you, don't hesitate to apply or get in touch with us if you have any questions!

🏢 Summary: Senior Java Developer role focused on designing and developing backend systems in a large-scale business environment. The position involves building new solutions, maintaining existing systems, and working in an agile DevOps-oriented team. Hybrid work model with one day per week in the Warsaw office. 🗂️ Requirements: Minimum 4 years of experience as Java Developer, Strong knowledge of Java, Strong knowledge of JEE, Experience with Spring, Experience with Hibernate, Experience with GIT, Knowledge of SQL, Experience with Oracle or PostgreSQL, Experience with Maven or Gradle, Knowledge of OOP, Knowledge of multithreading, Availability to work from Poland 📃 Skills: Java, JEE, Spring, Hibernate, GIT, SQL, Oracle, PostgreSQL, Maven, Gradle, OOP, Multithreading 🏢 Description: 🚀 Senior Java Developer | Hybryda Warszawa (1 dzień w tygodniu w biurze) Szukamy doświadczonego Java Developera, który chce mieć realny wpływ na rozwój nowoczesnych rozwiązań technologicznych w dużym środowisku biznesowym. Jeśli dobrze czujesz się w architekturze backendowej, lubisz pracę w zespole agile i cenisz sobie jakość kodu — możliwe, że właśnie na Ciebie czekamy. 🔥 💻 Co będziesz robić? • Współtworzyć i rozwijać systemy backendowe • Projektować oraz implementować rozwiązania dla nowych inicjatyw biznesowych • Dbać o jakość kodu, standardy i dokumentację techniczną • Wspierać testy akceptacyjne oraz wdrożenia • Brać udział w planowaniu iteracji, review i retrospektywach • Współpracować w zespole zwinnym w duchu DevOps • Stabilizować i rozwijać wdrożone rozwiązania 🛠️ Must have: • Minimum 4 lata doświadczenia jako Java Developer • Bardzo dobra znajomość Java/JEE • Spring + Hibernate • GIT • SQL oraz relacyjne bazy danych (Oracle/PostgreSQL) • Maven lub Gradle • Znajomość OOP oraz programowania wielowątkowego • Otwartość na pracę scrumową i nowe technologie • Możliwość świadczenia usług z terenu Polski ✨ Mile widziane: • Design Patterns • TDD / BDD • Kafka lub RabbitMQ • Docker / Kubernetes / Helm • GOSU • JavaScript / TypeScript / RxJS / HTML5 📍 Model pracy: Hybrydowo — 1 dzień w tygodniu z biura w Warszawie, reszta zdalnie. 🔥 Dlaczego warto? Praca przy rozwoju nowoczesnych rozwiązań, realny wpływ na produkt, dojrzały zespół technologiczny i przestrzeń do eksperymentowania z nowymi technologiami.

🏢 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: 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.