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: Senior Backend Java/Kotlin Developer role on a strategic energy-sector project focused on building and maintaining a highly available critical system. The position involves designing, developing, and supporting backend applications in an Agile SAFe environment with full BUILD & RUN ownership. Candidates will contribute to architecture, continuous improvement, and production support of industrial-grade systems. 🗂️ Requirements: Minimum 5 years of backend development experience, Strong proficiency in Java, Strong proficiency in Spring Boot, Strong proficiency in Kotlin, Experience with PostgreSQL, Experience with RabbitMQ or ActiveMQ, Experience with Ansible, Experience with Python, Experience working on critical or high-availability industrial systems, Strong BUILD & RUN culture, Experience working in Agile SAFe environment 📃 Skills: Java, Kotlin, Spring, PostgreSQL, RabbitMQ, ActiveMQ, Ansible, Python, SAFe, Agile 🏢 Description: Introduction & Résumé Nous recherchons un Développeur Backend Java/Kotlin Senior passionné pour rejoindre une équipe dynamique au sein d'un projet stratégique dans le secteur de l'énergie. Avec une expérience minimale de 5 ans et une maîtrise des technologies modernes telles que Java, Spring Boot et Kotlin, vous jouerez un rôle clé dans le développement d'un système critique à très haute disponibilité, représentant un enjeu majeur pour notre client. Main Responsibilities En tant que Développeur Backend, vous aurez pour responsabilités : Conception et développement de nouvelles fonctionnalités. Participation à l'architecture applicative. Tests, maintenance et amélioration continue. Prise en charge des applications jusqu'en production (BUILD & RUN). Analyse et correction des anomalies fonctionnelles et techniques. Participation à l'exploitation et au support des applications. Key Requirements 5 ans d'expérience minimum. Maîtrise de Java, Spring Boot, Kotlin, PostgreSQL, RabbitMQ ou ActiveMQ, Ansible et Python. Expérience impérative sur des SI critiques ou industriels à forte disponibilité. Forte culture BUILD & RUN. Environnement Agile SAFe. Nice to Have Expérience avec des outils de gestion de versions. Compréhension des pratiques DevOps. Other Details Ce poste est basé dans un environnement Agile et vous permettra de travailler sur des projets innovants dans un cadre collaboratif. Nous encourageons les candidatures à distance.

🏢 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: 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.

🏢 Summary: Oferta dotyczy roli Senior Backend Engineer odpowiedzialnej za rozwój wysokowydajnej platformy inwestycyjnej i tradingowej obsługującej miliony użytkowników. Stanowisko obejmuje projektowanie architektury mikroserwisowej, rozwój backendu w Java i Go oraz optymalizację systemów działających pod dużym obciążeniem. Kandydat będzie współpracować z zespołami Product, DevOps i Engineering oraz uczestniczyć w decyzjach architektonicznych i mentoringu. 🗂️ Requirements: 8-12 lat doświadczenia w programowaniu backendowym, Bardzo dobra znajomość Java, Bardzo dobra znajomość Golang, Doświadczenie z JVM, Doświadczenie w projektowaniu systemów high scale i high throughput, Bardzo dobra znajomość architektury mikroserwisowej, Doświadczenie z REST API, Doświadczenie z integracjami systemowymi, Znajomość MongoDB, Znajomość PostgreSQL, Znajomość MySQL, Znajomość indeksowania, cachingu i optymalizacji wydajności, Znajomość Linux, Znajomość podstaw sieci i komunikacji między komponentami, Umiejętność analizy logów i troubleshootingu, Doświadczenie w branży finansowej lub fintech, Znajomość języka angielskiego na poziomie B2 📃 Skills: Java, Golang, JVM, REST, MongoDB, PostgreSQL, MySQL, Linux, Microservices, API, Caching, Networking, AWS, GCP, Azure, Oracle, CI/CD, DevOps 🏢 Description: Dołącz do jednej z najszybciej rozwijających się firm technologicznych z sektora finansowego, która tworzy nowoczesną platformę inwestycyjną i tradingową wykorzystywaną przez użytkowników na całym świecie. To organizacja stawiająca na wysoką jakość inżynierii, skalowalność oraz nowoczesną architekturę. Produkty obsługują miliony użytkowników, bardzo duży ruch i wymagają rozwiązań zapewniających wysoką dostępność oraz wydajność. Twoja rola Jako Senior Backend Engineer będziesz odpowiadać za projektowanie i rozwój kluczowych komponentów platformy oraz współtworzenie architektury systemów działających pod dużym obciążeniem. Do Twoich obowiązków będzie należeć: projektowanie, rozwój i utrzymanie backendu w Java i Go, tworzenie oraz rozwój architektury mikroserwisowej, projektowanie i rozwój wydajnych API oraz integracji z systemami wewnętrznymi i zewnętrznymi, optymalizacja wydajności aplikacji oraz rozwiązywanie problemów produkcyjnych, analiza logów, diagnostyka i troubleshooting złożonych problemów, współpraca z zespołami Product, DevOps oraz Engineering przy dostarczaniu nowych funkcjonalności, udział w code review oraz dbanie o wysoką jakość kodu, mentoring mniej doświadczonych programistów, udział w podejmowaniu decyzji architektonicznych i rozwoju platformy. Szukamy osoby, która posiada 8-12 lat doświadczenia w programowaniu backendowym, bardzo dobrą znajomość Java i Golang, praktyczne doświadczenie z JVM, doświadczenie w projektowaniu i rozwijaniu systemów o wysokiej dostępności oraz dużym ruchu (high scale, high throughput), bardzo dobrą znajomość architektury mikroserwisowej, doświadczenie z REST API oraz integracjami systemowymi, praktyczną znajomość baz danych (MongoDB, PostgreSQL, MySQL), w tym indeksowania, cachingu i optymalizacji wydajności, dobrą znajomość systemu Linux oraz podstaw działania sieci i komunikacji między komponentami aplikacji, umiejętność diagnozowania problemów, analizy logów oraz proponowania usprawnień technicznych, doświadczenie w branży finansowej lub fintech, znajomość języka angielskiego na poziomie min. B2. Mile widziane doświadczenie z rozwiązaniami DevOps oraz CI/CD, znajomość chmur publicznych (AWS, GCP lub Azure), doświadczenie z Oracle Cloud, znajomość wzorców architektonicznych, doświadczenie w obszarze tradingu, giełdy, kryptowalut lub High-Frequency Trading (HFT), wykształcenie techniczne, znajomość języka arabskiego.

🏢 Summary: Senior Backend Developer (remote, 12-month contract) focused on building scalable data processing systems and robust data pipelines. The role involves designing system architecture, coding for scale, and collaborating across teams while experimenting with new technologies and MVPs. 🗂️ Requirements: BSc in Software Engineering, Computer Science or related field, 5+ years of experience with Python, Hands-on experience with data pipelines, Experience designing scalable system architectures, Experience in backend software development 📃 Skills: Python, AWS, CI/CD, DevOps, SQL, ElasticSearch, OpenSearch, Neptune, Neo4j 🏢 Description: Start: ASAP Work model: Remote Length of contract: 12 months + extensions We’re looking for a Senior Backend Developer with a data pipeline emphasis with a strong understanding of and hands-on experience with broad software development, i.e., system architecture, coding for scale, and communicating possibilities for what can be built and maintained, as well as a love for experimenting and building MVPs. Core Responsibilities: Design and implement software architectures for scalable data processing systems. Develop and maintain data pipelines for efficient data ingestion and processing. Collaborate with cross-functional teams to define and streamline software development processes. Participate in code reviews and maintain high software quality standards. Experiment with new technologies and frameworks to enhance system performance. Key Requirements: BSc in Software Engineering, Computer Science, or other relevant field 5+ years of experience with Python Experience with data pipelines Nice to Have: Experience with one or more AWS services AWS DevOps CI/CD Pipelines Relational databases ElasticSearch/OpenSearch Graph databases (e.g., Neptune or Neo4j)

🏢 Summary: Senior Backend Engineer role focused on building and scaling backend systems for an AI-driven product that transforms complex government data into actionable insights. The position involves designing data ingestion, processing pipelines, and distributed infrastructure from scratch, with full ownership from architecture to production. You will work closely with a small senior team to deliver scalable, production-ready systems. 🗂️ Requirements: 6+ years of Backend Engineering experience, Experience in JVM ecosystem, Experience in product companies (B2B SaaS preferred), Experience designing and owning backend systems in production, Strong knowledge of system design and scalability, Experience building asynchronous or distributed systems, Ability to make and justify technical decisions, Fluency in English, Valid work authorization in Europe or LATAM 📃 Skills: Kotlin, Java, JVM, SQL, GCP, Messaging, Queues, DistributedSystems, SystemDesign, DataPipelines, LLMs, AI 🏢 Description: About the role We’re looking for a Senior Backend Engineer to join our early team and help build our product from zero to one. You’ll work on a product that helps companies navigate complex government data, from contracts and grants to market signals and turn it into actionable insights using AI. On the backend side, this means working on data ingestion, processing, and the infrastructure that powers search and AI-driven workflows at scale. You’ll collaborate closely with a small, senior team and have real ownership, from shaping solutions to shipping them to production and improving them over time. You might be a fit if you: Must have: 6+ years of experience as a Backend Engineer, preferably in the JVM ecosystem (we use Kotlin on the backend) Experience working in product companies (B2B SaaS preferred) with direct impact on shipped features Experience working in small companies or startups would be a strong advantage Experience designing and owning backend systems in production (from initial design to deployment and ongoing improvements) Strong understanding of system design, including scalability, failure handling, and trade-offs Experience building asynchronous or distributed systems (e.g. messaging, queues, event-driven systems) Ability to make and justify technical decisions, not just implement given solutions Fluency in written and spoken English Nice to have: Experience with large-scale data processing, scraping, or data pipelines Experience working with LLMs / AI-related systems Experience with GCP or similar cloud environments How We Work Build Bridges to Help Customers Win - We pride ourselves on being obsessively customer-centric. Shooting Star Speed - We move with extreme speed. We value momentum, decisiveness, and the ability to accelerate when it matters. Fun Is a Feature - Fun is a Feature means we intentionally design Starbridge to be an energizing place to do hard work. Joy, humor, and camaraderie make great teams faster, sharper, and more resilient. In the Arena - We believe the best ideas come from living close to the work, feeling the friction, hearing the nuance, and experiencing the details firsthand. Benefits include: Competitive salary + early-stage equity Unlimited PTO Regular off-sites (NYC + global locations) Interview Process We move fast — really fast. Getting back to someone today beats tomorrow, and our interview process reflects that mindset. Please keep us posted on your timeline so we can move quickly and speed things up where needed. After submitting your application, the team reviews your CV and statement of exceptional work. If your application passes this stage, you will be invited to a 30-minute interview during which a member of our team will make sure you're a good fit for the role. You will have the opportunity ask questions and learn more about the role as well. We'll then send you a programming challenge that consists of two parts: LeetCode and SQL. Beyond that step, you will enter the main process, which consists of three interviews: System design exercise hands-on. Live coding in Java/Kotlin. Product thinking and past work. All interviews will be conducted via Google Meet. Eligibility to Work in Europe or LATAM: Candidates must hold valid authorization to work in the country where they will be based. At this time, we are unable to offer visa sponsorship or assist with work permit applications.

🏢 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: 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: Senior Backend Engineer role focused on building and maintaining scalable backend systems using NodeJs, Python, MongoDB, MQTT, and AWS. The position involves full lifecycle development, API and system design, code quality improvements, mentoring junior engineers, and contributing to technical strategy. Candidates should have strong backend engineering experience, testing knowledge, and familiarity with CI/CD and monitoring practices. 🗂️ Requirements: 4+ years of professional experience with NodeJs, 4+ years of professional experience with Python, 4+ years of professional experience with MongoDB, 4+ years of professional experience with MQTT, 4+ years of professional experience with AWS, Backend development experience, Experience building web applications and APIs, Ability to write clean, maintainable code, Knowledge of SOLID principles, Experience with testing strategies and implementations, System design experience from ambiguous requirements, Understanding of CI/CD practices, Experience with logging and monitoring tools, Knowledge of version control best practices 📃 Skills: NodeJs, Python, MongoDB, MQTT, AWS, Go, APIs, CI/CD, SOLID, Git, Testing, Monitoring, Logging 🏢 Description: Introduction & Summary: We are seeking an experienced Senior Backend Engineer who will be responsible for building and maintaining robust backend systems. The ideal candidate will possess a strong background in backend development, particularly with NodeJs, Python, MongoDB, MQTT, and AWS. A proactive problem-solver with a focus on clean, maintainable code and system design will thrive in this role. Main Responsibilities: Participate in all stages of the development and post-development lifecycle Proactively provide creative, thorough, and practical solutions to technical problems Design, write, and maintain well-organized, scalable, and testable code Identify and address issues and bottlenecks, advocating for changes Promote best practices and code quality within the team Contribute to refining technical vision and aligning it with business objectives Mentor and guide junior engineers Key Requirements: Hands-on experience in backend development and engineering At least 4 years of professional experience with NodeJs, Python, MongoDB, MQTT, and AWS Experience with GO is advantageous Proven experience in building web applications and APIs Ability to write clean, maintainable code and apply SOLID principles Experience with various testing strategies and implementations Capability to design systems from ambiguous product requirements Understanding of continuous integration and delivery Proficiency with logging and monitoring tools Knowledge of version control best practices Proactive mindset emphasizing continuous improvement and learning Nice to Have: Strong problem-solving skills and critical thinking regarding technical challenges Flexibility and willingness to adapt to changing priorities and technologies Other Details: This role offers a dynamic work environment with opportunities for growth and development. Ideal candidates will commit to excellence and a proactive approach in their work.