Senior Backend developer (Kotlin/Java)

🏢 Summary: The role involves designing and developing scalable backend systems in a microservices architecture using Java or Kotlin and Spring. The engineer will influence technical decisions while building payment and subscription platforms with event-driven communication and cloud-based solutions. The position includes working with modern architectural patterns and ensuring high code quality through testing and reviews. 🗂️ Requirements: Strong experience with Java and/or Kotlin, Solid knowledge of Spring and Spring Boot, Hands-on experience with SQL and relational databases, Experience with PostgreSQL, Proven experience with microservices architecture, Experience with event-driven systems, Practical experience with JUnit, Mockito, Testcontainers, Experience with AWS or GCP, Understanding of DDD, CQRS, Hexagonal Architecture, Experience with payment or subscription systems 📃 Skills: Java, Kotlin, Spring, SpringBoot, SQL, PostgreSQL, Microservices, Kafka, JUnit, Mockito, Testcontainers, AWS, GCP, DDD, CQRS, HexagonalArchitecture 🏢 Description: Senior Backend Engineer (Java/Kotlin) We are looking for an experienced Backend Engineer to join a team building modern, scalable systems based on a microservices architecture. This role offers real influence over technical decisions, system architecture, and the quality of delivered solutions—particularly within payment and subscription platforms. Responsibilities Design, develop, and maintain backend systems using Java or Kotlin and the Spring Framework Build and evolve microservices following DDD , CQRS , and Hexagonal Architecture principles Implement event-driven communication , ideally using Apache Kafka Work with relational databases ( PostgreSQL or other SQL databases ) and optimize queries Write unit and integration tests using JUnit, Mockito, and Testcontainers Contribute to the design and development of cloud-based solutions ( AWS or GCP ) Participate in code reviews and drive high engineering standards Collaborate closely with product and engineering teams to deliver business-critical features Requirements Strong experience with Java and/or Kotlin Solid knowledge of Spring / Spring Boot Hands-on experience with SQL and relational databases (preferably PostgreSQL ) Proven background in microservices-based architectures Experience with event-driven systems (Kafka is a strong plus) Practical experience with backend testing (JUnit, Mockito, Testcontainers) Experience working with cloud platforms ( AWS or GCP ) Good understanding of Domain-Driven Design (DDD) , CQRS , and Hexagonal Architecture Must-have: experience with payment systems and/or subscription-based platforms Nice to Have Experience working with high-scale, high-availability systems Knowledge of security and transactional data handling Background in product-driven, Agile environments

🏢 Summary: Backend Developer role focused on designing and building scalable, cloud-based applications using Java and Spring Boot in a microservices architecture. The position involves developing and deploying distributed, event-driven services on Azure using modern containerization and API technologies. The offer emphasizes building reliable, high-quality backend systems with up-to-date cloud-native practices. 🗂️ Requirements: Strong Java development experience, Experience with Spring Boot, Experience with microservices architecture, Experience with cloud-native applications, Familiarity with Azure, Knowledge of Kafka or similar messaging systems, Understanding of GraphQL or REST APIs, Experience with Docker, Experience with Kubernetes 📃 Skills: Java, Spring, SpringBoot, Microservices, Azure, Kafka, GraphQL, REST, Docker, Kubernetes 🏢 Description: We are seeking a talented Backend Developer to join our team, contributing to the design and development of modern, cloud-based applications. The role focuses on building scalable and maintainable services using up-to-date technologies and best practices. Key Responsibilities: Develop and maintain backend services using Java and Spring Boot . Build and support microservices solutions for distributed systems. Work with cloud platforms such as Azure , including event-driven architectures. Implement and consume APIs using GraphQL or REST. Package and deploy applications using Docker and Kubernetes . Collaborate with team members to deliver reliable, high-quality software. Required Skills & Experience: Strong background in Java development with Spring Boot . Experience with microservices and cloud-native applications. Familiarity with Azure , Kafka , or similar messaging/event systems. Understanding of API design ( GraphQL /REST). Practical experience with containerization ( Docker , Kubernetes ). Nice to Have: Knowledge of CI/CD practices and automated deployments. Experience with monitoring, logging, or observability in distributed systems.

🏢 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 implementing enterprise-grade backend solutions using modern architecture principles. The position emphasizes high code quality, performance, security, and collaboration within a distributed team. The role involves working with Java 17+, Spring ecosystem, databases, and event-driven systems. 🗂️ Requirements: Minimum 5 years of commercial software development experience, Very good knowledge of Java 17+, Strong understanding of object-oriented design patterns, Experience with Spring MVC and Spring Data, Experience with Apache Kafka, Ability to design relational and non-relational databases (MS SQL, Oracle, Elasticsearch, Redis), Knowledge of software engineering best practices, English proficiency for technical documentation, Ability to work effectively in a distributed team 📃 Skills: Java, Spring, SpringMVC, SpringData, Kafka, MSSQL, Oracle, Elasticsearch, Redis, OOP, UML, Docker, Kubernetes, Azure, JavaScript, React, Python 🏢 Description: We are looking for an experienced Senior Java Developer with at least 5 years of commercial experience to join a team working on enterprise-grade backend solutions. The role focuses on designing and implementing software in a modern architecture, with a strong emphasis on code quality, performance, security, and effective collaboration within a distributed team. Responsibilities Design and implement software using hexagonal architecture. Develop backend solutions using Java 17+ and the Spring ecosystem. Ensure high code quality and compliance with agreed development standards. Analyse system performance, security, and stability, and propose improvements. Design and optimise data structures for relational and non-relational databases. Collaborate with a distributed team, participate in technical analysis, code reviews, and solution design. Identify technical challenges and propose improvements to architecture and implementation. Requirements Minimum 5 years of commercial software development experience. Very good knowledge of Java 17+. Strong understanding of object-oriented design patterns and software engineering best practices. Experience with the Spring stack, especially Spring MVC and Spring Data. Knowledge of Apache Kafka. Ability to design databases: relational: MS SQL, Oracle, non-relational: Elasticsearch, Redis. English skills sufficient to work with technical documentation. Strong analytical and creative problem-solving skills. Excellent communication skills and ability to work effectively in a distributed team. Nice to have Knowledge of scripting/frontend technologies such as JavaScript, React, Python. Experience working in an Azure cloud environment. Familiarity with Kubernetes and Docker. Ability to design system architecture and prepare High-Level Design (HLD) documentation. Knowledge of UML and flow diagrams.

🏢 Summary: Backend Engineer role focused on Java EE development, DevOps automation, and infrastructure management for a global mobile wallet platform processing billions of transactions. The position involves building CI/CD pipelines, managing Kubernetes and Docker environments, and improving observability in an agile remote team setup. Candidates will work with modern backend and cloud-native technologies to support large-scale financial services. 🗂️ Requirements: 3+ years of Java development experience, Hands-on experience with Kubernetes, Hands-on experience with Docker, Experience with CI/CD automation, Knowledge of Gradle, Knowledge of Maven, Experience with Apache Kafka, Experience with SQL, Experience with Oracle, English proficiency at B2 level or higher 📃 Skills: Java, JavaEE, Kotlin, Kafka, Docker, Kubernetes, Jenkins, GitLab, Gradle, Maven, SQL, Oracle, OpenTelemetry 🏢 Description: Role Overview: Are you a developer who loves to own the entire lifecycle of an application? We are looking for a Backend Engineer with a strong DevOps mindset to bridge the gap between code and infrastructure for our global Mobile Wallet Platform. Key Responsibilities: - Backend development (Java EE) with a focus on automation and deployment - Configuring and managing Docker and Kubernetes environments - Building and maintaining CI/CD pipelines (Jenkins, GitLab CI) - Optimizing system observability using OpenTelemetry and logging tools Requirements: - 3+ years of experience in Java development - Hands-on experience with Kubernetes and Docker is mandatory - Proficiency in CI/CD automation and Gradle/Maven - Experience with Apache Kafka and SQL/Oracle - Fluent English (B2+) Project Context: - Scale: Handling billions of transactions globally - Tech Stack: Java EE, Kotlin, Kafka, Docker, Kubernetes, OpenTelemetry - Location: Remote with occasional visits to the Warsaw office (approx. once a month) - Team: Agile setup (5-7 people) - Impact: Enabling financial inclusion for the unbanked populations worldwide

🏢 Summary: Backend Engineer role focused on developing and maintaining a global Mobile Wallet Platform, combining Java backend development with DevOps responsibilities. The position involves managing containerized environments, building CI/CD pipelines, and improving system observability in a high-scale transaction system. Remote work with occasional on-site presence in Warsaw. 🗂️ Requirements: 3+ years of Java development experience, Hands-on experience with Kubernetes, Hands-on experience with Docker, Experience with CI/CD automation, Proficiency with Gradle or Maven, Experience with Apache Kafka, Experience with SQL or Oracle databases, English level B2 or higher 📃 Skills: Java, JavaEE, Kotlin, Docker, Kubernetes, Jenkins, GitLabCI, Gradle, Maven, Kafka, SQL, Oracle, OpenTelemetry 🏢 Description: Role Overview: Are you a developer who loves to own the entire lifecycle of an application? We are looking for a Backend Engineer with a strong DevOps mindset to bridge the gap between code and infrastructure for our global Mobile Wallet Platform. Key Responsibilities: Backend development (Java EE) with a focus on automation and deployment . Configuring and managing Docker and Kubernetes environments. Building and maintaining CI/CD pipelines (Jenkins, GitLab CI). Optimizing system observability using OpenTelemetry and logging tools Requirements: 3+ years of experience in Java development. Hands-on experience with Kubernetes and Docker is mandatory. Proficiency in CI/CD automation and Gradle/Maven. Experience with Apache Kafka and SQL/Oracle. Fluent English (B2+). Project Context Scale: Handling billions of transactions globally. Tech Stack: Java EE, Kotlin, Kafka, Docker, Kubernetes, OpenTelemetry. Location: Remote with occasional visits to the Warsaw office (approx. once a month). Team: Agile setup (5-7 people). Impact: Enabling financial inclusion for the unbanked populations worldwide.

🏢 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: 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 Fullstack Developer role focused on designing and building secure, scalable microservices and modern SPA applications in an international environment. The position is hands-on, backend-oriented with active frontend development, emphasizing high code quality, event-driven architecture, and strong security standards. The role includes architecture contribution, CI/CD implementation, and maintaining large-scale systems. 🗂️ Requirements: Strong fullstack development experience (backend and frontend), Senior-level hands-on coding experience, Expertise in Java 17–21, Experience with Spring Boot 3.x microservices, Experience with Kafka and event-driven architecture, Strong SQL knowledge (Oracle), Experience with Redis, Experience with Angular SPA development, Strong TypeScript knowledge, Knowledge of Node.js, Understanding of DDD, Knowledge of web security principles, Experience with OIDC and OAuth2, Experience with CI/CD pipelines, Experience with large-scale applications, Fluent English, Availability to work from Warsaw office 2x/week 📃 Skills: Java, SpringBoot, Kafka, SQL, Oracle, Redis, DDD, Node.js, TypeScript, Angular, Webpack, OIDC, OAuth2, OWASP, Git, GitLab, Jenkins, Maven, Docker, Kubernetes, IntelliJ, VSCode, Jira, Confluence, Python, CICD 🏢 Description: Mission & Responsibilities As a Senior Fullstack Developer, you will design, build, and maintain modern, secure, and scalable applications that support critical business processes. You will work hands-on across both backend and frontend, contributing directly to software development rather than people management. Your mission is to ensure service continuity, high code quality, and alignment with business and security standards, while actively collaborating with international stakeholders in an English-speaking environment. Key Responsibilities Design, develop, and maintain fullstack applications (backend-focused with modern frontend) Build secure, scalable, maintainable, and testable software Develop Java-based microservices using Spring Boot Contribute to Single Page Applications (SPA) development Collaborate with business and technical stakeholders on requirements Participate in architecture design and technical decisions Integrate systems using event-driven architectures (Kafka) Optimize and maintain existing codebases Implement automated testing and CI/CD pipelines Ensure application security (authentication, identity management) Maintain technical documentation Share best practices within developer communities Continuously improve skills and stay up to date with modern technologies Requirements Backend & Architecture Java 17–21 (modern Java, no legacy) Spring Boot 3.x (microservices) Kafka (event-driven systems) SQL (Oracle) Redis (experience or strong understanding) Domain Driven Design (DDD) Frontend Node.js TypeScript Angular (SPA development) Strong knowledge of Angular best practices Webpack (nice to have) Security Strong web security knowledge OIDC & OAuth2 Identity management platforms (nice to have) OWASP awareness (certifications are a plus) DevOps & Tools Git CI/CD: GitLab CI (Jenkins nice to have) Maven (nice to have) Docker & Kubernetes (nice to have) IntelliJ, VS Code Jira & Confluence Additional Python (nice to have) AI-based coding tools (nice to have) Ways of Working Agile (Scrum, Kanban) DevOps mindset Distributed, international collaboration Soft Skills Strong teamwork and collaboration Analytical and problem-solving mindset Independent work on complex topics Adaptability and results-driven attitude Continuous learning mindset Candidate Profile (Must-have) Strong fullstack experience (backend-only profiles will not be considered) Senior-level hands-on developer (not a manager or lead) Experience with large-scale applications Excellent English communication skills Willingness to work from the office in Warsaw 2x/week If you're a hands-on engineer who enjoys building high-quality systems and working in an international environment — we’d love to hear from you.

🏢 Summary: The offer is for a Java Backend Developer role focused on building and maintaining microservices-based systems using Java and Spring technologies. The position involves developing REST APIs, working with containerized applications, and contributing to Agile delivery processes. The role centers on backend engineering, technical design, and collaboration within cross-functional teams. 🗂️ Requirements: Minimum 3+ years professional experience in backend development, Proficiency in Java 8+, Strong experience with Spring Boot and Spring technologies, Experience building microservices, Experience working with REST APIs, Knowledge of HTTPS, SFTP, REST and SOAP protocols, Understanding of microservices architecture and containerization, Experience with Kafka, Experience with Git and GitHub, Experience with Maven and Jenkins, Experience with MySQL and SQL databases, Familiarity with Linux, Experience working in Agile/Scrum environments 📃 Skills: Java, Spring, SpringBoot, REST, Microservices, Kafka, HTTPS, SFTP, SOAP, Linux, Git, GitHub, Maven, Jenkins, Jira, MySQL, SQL, Containerization, Agile 🏢 Description: Job Description: We are looking for skilled Java Backend Developers with strong experience in Java, Spring technologies, and microservices architecture. The ideal candidate will have hands-on expertise in backend development, REST APIs, containerized applications, and Agile delivery environments. Qualifications: Minimum 3+ years of relevant professional experience Proficiency in Java 8+, REST APIs, Spring Boot, and Spring technologies Experience in building microservices and working with Kafka Solid understanding of HTTPS, SFTP, REST API, and SOAP protocols Familiarity with Linux operating systems Strong understanding of microservices architecture and containerization Knowledge of Agile frameworks and principles Experience with Git/GitHub, GitHub Actions, Maven, Jenkins, and Jira Competence with MySQL and SQL databases Strong analytical and problem-solving skills Excellent written and verbal communication skills Ability to collaborate effectively with Product, QA, DevOps, and Agile/Scrum teams Mandatory Skills: Java (Spring) REST APIs Spring Boot and Spring Technologies HTTPS, SFTP, REST API, and SOAP protocols Microservices architecture and containerization Git/GitHub, GitHub Actions, Maven, Jenkins, Jira MySQL and SQL databases Desired Skills: Strong analytical and troubleshooting abilities Excellent communication skills Team collaboration experience within Agile/Scrum environments Roles & Responsibilities: Contribute to technical design and engineering activities Develop strong domain expertise within the project Analyse functional and technical requirements Support architecture and design discussions Collaborate with Architecture and Business teams Participate in development, design, code reviews, and implementation Follow engineering best practices and support continuous improvement initiatives Out of Scope: Creating product requirements Acting as Scrum Master or Product Owner Project Details: Primary focus is on Java backend development.