Node.js Backend Developer

🏢 Summary: Long-term B2B opportunity for a senior engineer to deliver production-ready code and shape system architecture in a microservices environment. The role combines hands-on Java and React development with architectural responsibilities in a global, collaborative setup. It focuses on high-frequency delivery and technical excellence within the financial sector. 🗂️ Requirements: Strong Java experience (latest versions), Strong React experience, Experience with microservices architecture, Experience delivering RESTful APIs, Experience with PostgreSQL, Proven high-frequency code delivery, Experience in banking or financial sector 📃 Skills: Java, React, Microservices, REST, PostgreSQL, Banking, Docker, Kubernetes 🏢 Description: Working mode : Hybrid - 6 days per month at the Warsaw office Contract type : B2B, long term cooperation Rate : 200 PLN/h Summary: This role focuses on hands-on development and system architecture, driving engineering culture, and enhancing business growth through technical expertise in a collaborative, global environment. Main Responsibilities: Deliver code to production and support system architecture aligned to microservices Understand business, engineering, and non-functional requirements Drive the desired engineering culture across teams Collaborate with a globally diverse team across regions Proactively remove impediments, assess risks, and communicate issues to program management Identify and eliminate process inefficiencies Key Requirements: Strong Java and React programming experience Experience in microservice architecture Background in the financial sector, particularly banking Proven capability of delivering code changes at high frequency Experience with RESTful API delivery Familiarity with PostgreSQL databases Recent Java experience, preferably with the latest versions Experience with ReactJS for UI application development Nice to Have: Knowledge of containers and orchestration technologies like Docker and Kubernetes. Other Details: This position offers the opportunity to work within a multi-regional team on innovative projects. Ideal for candidates seeking to leverage their development skills in a dynamic and evolving business context.

🏢 Summary: Long-term B2B hybrid role focused on hands-on Java and React development within a microservices architecture, contributing directly to production code and system design. The position emphasizes high-frequency delivery, REST API development, and collaboration in a global engineering environment. It combines technical leadership with active development in financial-sector projects. 🗂️ Requirements: Strong experience with Java, Strong experience with ReactJS, Experience with microservices architecture, Experience delivering RESTful APIs, Experience with PostgreSQL, Recent experience with modern Java versions, Ability to deliver code changes frequently, Background in banking or financial sector 📃 Skills: Java, ReactJS, Microservices, REST, PostgreSQL, Docker, Kubernetes 🏢 Description: Working mode: Hybrid - 6 days per month at the Kraków office Contract type: B2B, long term cooperation Rate: 200 PLN/h Summary: This role focuses on hands-on development and system architecture, driving engineering culture, and enhancing business growth through technical expertise in a collaborative, global environment. Main Responsibilities: Deliver code to production and support system architecture aligned to microservices Understand business, engineering, and non-functional requirements Drive the desired engineering culture across teams Collaborate with a globally diverse team across regions Proactively remove impediments, assess risks, and communicate issues to program management Identify and eliminate process inefficiencies Key Requirements: Strong Java and React programming experience Experience in microservice architecture Background in the financial sector, particularly banking Proven capability of delivering code changes at high frequency Experience with RESTful API delivery Familiarity with PostgreSQL databases Recent Java experience, preferably with the latest versions Experience with ReactJS for UI application development Nice to Have: Knowledge of containers and orchestration technologies like Docker and Kubernetes. Other Details: This position offers the opportunity to work within a multi-regional team on innovative projects. Ideal for candidates seeking to leverage their development skills in a dynamic and evolving business context.

🏢 Summary: B2B contract for a Senior Java Developer to design, implement, and modernize a large-scale Terminal Management System handling 300k+ payment terminals. The role focuses on developing and migrating distributed systems components using Spring Boot and WildFly, integrating multiple internal and external services, and improving security through vulnerability scanning and upgrades. 🗂️ Requirements: Very good knowledge of Java 8+, Strong object-oriented programming skills, Experience in designing, implementing, documenting and testing application components, Very good practical knowledge of Spring and Spring Boot, Very good practical knowledge of Hibernate/JPA and JEE, Experience with message queue systems, especially RabbitMQ, Knowledge of Maven, Git, GitLab, GitLab CI/CD, Jenkins, Nexus, Jira, Knowledge of relational databases, particularly Oracle, Practical knowledge of RESTful API design, Experience in system integration, Experience with distributed systems, Experience with JBoss/WildFly application servers, Knowledge of security scanning tools (e.g., Fortify, Sonatype), Availability to work 4 days per week from Warsaw office, Full availability in Polish time zone 📃 Skills: Java, Spring, SpringBoot, Hibernate, JPA, JEE, RabbitMQ, Maven, Git, GitLab, Jenkins, Nexus, Jira, Oracle, REST, JBoss, WildFly, Fortify, Sonatype, Hazelcast, GWT, GWTExt, SOAP, RMI 🏢 Description: The client is an American multinational company in the fintech industry Key details: Location: 4 days/week from the Warsaw office Rate: 130–180 PLN/hour net + VAT Job type: B2B contract Duration: 12 months + extensions Recruitment process: 2 stages English and Polish: B2/B2+ Luxmed, MultiSport, equipment provided by the client Job Responsibilities Design and implementation of IT solutions based on the presented analytical and technical documentation; Reviewing analytical documentation; Creating technical documentation; Technical upgrade for existing system; Working with legacy code Conducting regular scans in the application and removing vulnerabilities Job Requirements Fully available in the Polish time zone; Ability to work from the office in Warsaw (weekly: 4 days at office + 1 day WFH ); Very good knowledge of Java 8+ and object-oriented programming issues; Experience in independent design, implementation, documentation and testing of application components; Very good and p ractical knowledge of Spring, Spring Boot, Hibernate/JPA and JEE frameworks; Practical knowledge with message queue systems, particularly RabbitMQ; Practical knowledge of tools supporting the software development process: Maven, Git, Gitlab, Gitlab CI/CD, Jenkins, Nexus, Jira; Knowledge of relational databases, in particular Oracle; Practical knowledge of RESTful API design; Experience in system integration; Experience with distributed systems; Experience with application servers, JBoss/WildFly; Knowledge of scannnfg tools (Fortify, Sonatype..) Description of the area of involvement TMS (Terminal Management System) is used to manage a very large number of payment terminals (300k+), it gives users a uniform way to manage different terminals from different hardware vendors. TMS has a complex architecture, consisting of two components TMS (1 WildFly instance) providing GUI and implementing some business functions and RTMS (3 Spring-boot instances) implementing most of the business functionalities. A gradual migration from TMS to RTMS is being carried out. The system intensively uses Spring, Hibernate and RabbitMQ. The system has distributed transactions (different two-phase-commit, saga approaches) and distributed cache (Hazelcast). TMS is integrated with many internal and external systems (via REST, SOAP, RMI, direct database connections and database links). The GUI is written in GWT and GWTExt. Hays Poland sp. z o.o. is an employment agency registered in a registry kept by Marshal of the Mazowieckie Voivodeship under the number 361

🏢 Summary: Remote B2B offer for a Node.js engineer to support a project involving scalable, distributed web systems and microservices. The role focuses on building high-performance applications using JavaScript/TypeScript in cloud environments with AWS and Docker. Work includes backend development, database integration, automated testing, and CI/CD processes. 🗂️ Requirements: Minimum 3 years experience in building scalable web applications, Strong knowledge of JavaScript or TypeScript, Very good knowledge of Node.js and Nest.js, Experience with distributed architecture and microservices, Good knowledge of relational databases (PostgreSQL or MySQL), Experience writing unit and integration tests (Jest or Mocha), Knowledge of CI/CD processes, Experience with AWS (S3, SQS, Lambda), Experience with Docker 📃 Skills: JavaScript, TypeScript, Node.js, Nest.js, PostgreSQL, MySQL, Jest, Mocha, AWS, S3, SQS, Lambda, Docker, CI/CD, Microservices, MVC, CQRS 🏢 Description: Kim jesteśmy? Jesteśmy firmą programistyczną specjalizującą się w tworzeniu szytych na miarę, aplikacji webowych i mobilnych. Pracujemy dla klientów z całego świata – z USA, UK, Niemiec, Holandii, Skandynawii i innych. Tworzymy systemy od prostych API opartych o kontenery, poprzez systemy złożone z mikroserwisów, kończąc na rozwiązaniach Cloud Native. A to wszystko dla klientów m.in. z branży fintech, medtech, e-commerce. Kochamy programowanie oraz JS i TS, najbardziej Reacta i Node.js! Aktualnie poszukujemy inżynierów, którzy byliby zainteresowani wsparciem jednego z naszych projektów (rekrutacja pod projekt). Wynagrodzenie: B2B : 9 500 - 16 000 zł + VAT Miejsce pracy: Współpraca 100% zdalna, bez konieczności pojawiania się w biurze! Jeśli jednak chcesz pracować z biura, mamy dwie opcje - Warszawa, ul. Złota 59 oraz Gliwice, ul. Dolnych Wałów 8. Od Ciebie oczekujemy: co najmniej 3 lat doświadczenia w budowaniu zaawansowanych, wydajnych i skalowalnych aplikacji internetowych znajomości współczesnego użycia JavaScript lub TypeScript (MVC, CQRS, dependency injection) dobrej znajomości Node.js (Nest.js) doświadczenia w pracy w architekturze rozproszonej, mikroserwisach dobrej znajomości relacyjnych baz danych (PostgreSQL / MySQL) umiejętności pisania testów jednostkowych oraz integracyjnych w jednym z popularnych frameworków (Jest, Mocha, etc.) oraz znajomości automatyzacji procesów (CI/CD) doświadczenia w pracy z AWS (S3, SQS, Lambda) umiejętności pracy z Dockerem dobrej znajomości języka angielskiego umożliwiającej swobodną komunikację w zespole międzynarodowym - warunek konieczny zaangażowania, samodzielności, proaktywności oraz odpowiedzialności za projekt dostępność do podjęcia pracy w przeciągu ok. 1 miesiąca Mile widziane: doświadczenie w wykorzystaniu w pracy narzędzi AI (Copilot, Cursor itp.) znajomość Kubernetesa i Terraforma doświadczenie w branży fintech

🏢 Summary: Remote B2B offer for a Senior Fullstack JavaScript/TypeScript Engineer to build scalable web applications in distributed, microservices and cloud-native architectures. The role involves working with React and Node.js (Nest) on international projects, covering both frontend and backend layers. The position requires strong experience with AWS, Kubernetes and modern DevOps practices. 🗂️ Requirements: Minimum 5 years of experience building scalable web applications, Strong knowledge of JavaScript or TypeScript (MVC, CQRS, dependency injection), Very good knowledge of Node.js and Nest, Very good knowledge of React, Experience with distributed architecture and microservices, Knowledge of scalable system architecture and inter-service communication, Experience with AWS (S3, SQS, Lambda), Knowledge of Kubernetes and Terraform, Very good knowledge of PostgreSQL or MySQL and SQL, Ability to write unit and integration tests (Jest, Mocha or similar), Experience with CI/CD automation, Very good English skills (B2 or higher), Availability to start within 1 month 📃 Skills: JavaScript, TypeScript, Node.js, Nest, React, AWS, S3, SQS, Lambda, Kubernetes, Terraform, PostgreSQL, MySQL, SQL, Jest, Mocha, CI/CD, Microservices, MVC, CQRS 🏢 Description: Kim jesteśmy? Jesteśmy firmą programistyczną specjalizującą się w tworzeniu szytych na miarę, aplikacji webowych i mobilnych. Pracujemy dla klientów z całego świata – z USA, UK, Niemiec, Holandii, Skandynawii i innych. Tworzymy systemy od prostych API opartych o kontenery, poprzez systemy złożone z mikroserwisów, kończąc na rozwiązaniach Cloud Native. A to wszystko dla klientów m.in. z branży fintech, medtech, e-commerce. Kochamy programowanie oraz JS i TS, najbardziej Reacta i Node.js! Aktualnie poszukujemy inżynierów, którzy byliby zainteresowani wsparciem jednego z naszych projektów (rekrutacja pod projekt). Wynagrodzenie: B2B : 17 000 - 26 000 zł + VAT Miejsce pracy: Praca 100% zdalna, bez konieczności pojawiania się w biurze! Jeśli jednak chcesz pracować z biura, mamy dwie opcje - Warszawa, ul. Złota 59 oraz Gliwice, ul. Dolnych Wałów 8 Od Ciebie oczekujemy: co najmniej 5 lat doświadczenia w budowaniu zaawansowanych, wydajnych i skalowalnych aplikacji internetowych znajomości współczesnego użycia JavaScript lub TypeScript (MVC, CQRS, dependency injection) dobrej znajomości Node.js (Nest) oraz React.js doświadczenia w pracy w architekturze rozproszonej, mikroserwisach znajomości rozwiązań architektonicznych w budowaniu wydajnych i skalowalnych aplikacji (komunikacja między serwisami, kolejki) doświadczenia w pracy z AWS (S3, SQS, Lambda) znajomości Kubernetesa i Terraforma bardzo dobrej znajomości relacyjnych baz danych (PostgreSQL / MySQL) i języka SQL, umiejętności pisania testów jednostkowych oraz integracyjnych w jednym z popularnych frameworków (Jest, Mocha, etc.) oraz znajomości automatyzacji procesów (CI/CD) dobrej znajomości języka angielskiego umożliwiającej swobodną komunikację w zespole międzynarodowym - warunek konieczny zaangażowania, proaktywności oraz odpowiedzialności za całość projektu (zarówno warstwę FE, jak i BE) dostępność do podjęcia pracy w przeciągu ok. 1 miesiąca Mile widziane: doświadczenie w wykorzystaniu w pracy narzędzi AI (Copilot, Cursor itp.) doświadczenie w branży fintech doświadczenie w Next.js znajomość Playwright znajomość frameworka Koa

🏢 Summary: Backend engineering role in the Advertising team focused on building and operating high-performance, cloud-native microservices and ML infrastructure at massive scale. The position involves designing distributed systems, data streaming solutions, and end-to-end ML serving pipelines in a real-time marketplace environment. Engineers own services end-to-end, from design to deployment, within a modern Kotlin-based tech stack. 🗂️ Requirements: Proficiency in Kotlin or Java, Experience building high-performance, high-availability backend systems, Experience with distributed systems and microservices architecture, Experience with data streaming systems, Experience with cloud-native environments, Ability to design and deploy ML serving infrastructure, English at B2 level or higher 📃 Skills: Kotlin, Java, Spring, Kafka, Kubernetes, BigQuery, Spark, Docker, Consul, GitHub, GitHubActions, ML 🏢 Description: Important things for you Flexible working hours in the hybrid model (4/1) - working hours start between 7:00 a.m. and 10:00 a.m. We also have 30 days of occasional remote work. The salary range for this position depending on the skill set is as follows (contract of employment, tax-deductible cost): PLN 11 200 - 15 250 Annual bonus based on your annual performance and company results. Our team is based in Warsaw. About the job Massive Scale : Design, build, and optimize systems that handle thousands of requests per minute. This is high-availability, high-performance engineering in practice. Modern Tech Stack : Work with a world-class, cloud-native environment. Our core technologies include Kotlin, Spring, Kafka, and Kubernetes. We're not shy when it comes to ML too :) True Ownership & Autonomy : We live by a "you build it, you run it" philosophy. You'll join an agile, autonomous team with full ownership of your microservices, from design to deployment. Complex Challenges : From distributed systems and data streaming to algorithmic optimization, you'll tackle the complex backend problems that power a massive, real-time marketplace. End-to-End ML Systems: Bridge the gap between big data and real-time product impact. You’ll build the infrastructure for serving ML models , using BigQuery and Apache Spark for offline data processing. You’ll integrate these components with our microservices architecture to create the sophisticated advertising system that powers a personalized user experience. Join the Advertising team! You will have a chance to build Allegro Ads - one of the most visible products on the platform. Your team works closely with the Machine Learning team, creating the best experience for customers. High performance, engineering best practices and great atmosphere in the team guaranteed! We are looking for people who: Code in Kotlin or Java and are eager to master Kotlin by taking part greenfield project Want to be proud of the code they create ; they value high-quality code reviews and engage in substantive discussions on software engineering best practices; Are excited about building new products and want to experience the journey of launching a fresh project within the Allegro ecosystem; Are open to developing soft skills and embracing a growth mindset through active participation in code reviews, pair programming, and team retrospectives.; Are open to incorporating AI coding assistants into their daily work to maximize efficiency and focus on complex problem-solving Can look for effective solutions to the requirements set by users; Want to constantly develop and update their knowledge; Know English at at least B2 level. What's in it for you: Well-located offices (with e.g. fully equipped kitchens, bicycle parking, terraces full of greenery) and excellent work tools (e.g., raised desks, ergonomic chairs, interactive conference rooms). A 16" or 14" MacBook Pro or corresponding Dell with Windows (if you don't like Macs) and all the necessary accessories. A wide selection of fringe benefits in a cafeteria plan - you choose what you like (e.g., medical, sports or lunch packages, insurance, purchase vouchers). English classes that we pay for related to the specific nature of your job. A training budget, inter-team tourism ( see more here ), hackathons, and an internal learning platform where you will find multiple trainings. An additional day off for volunteering, which you can use alone, with a team, or with a larger group of people connected by a common goal. Social events for Allegro people - Spin Kilometers, Family Day, Fat Thursday, Advent of Code, and many other occasions we enjoy. And that's just the beginning! You can read more about the benefits here . #goodtobehere means that: You will join a team you can count on - we work with top-class specialists who have knowledge- and experience-sharing in their DNA. You will love our level of autonomy in team organization, the space for continuous development, and the opportunity to try new things. You get to choose which technology solves the problem and you are responsible for what you create. You will value our Developer Experience and the full platform of tools and technologies that make creating software easier. We rely on an internal ecosystem based on self-service and widely used tools such as Kubernetes, Docker, Consul, GitHub, and GitHub Actions. Thanks to this, you can contribute to Allegro from your very first days on the job. You will be equipped with modern AI tools to automate repetitive tasks, allowing you to focus on developing new services and refining existing ones (also leveraging AI support). You will create solutions that will be used (and loved!) by your friends, family and millions of our customers. You will meet the Allegro Scale , which starts with over 1000 microservices, an open-source data bus (Hermes) with 300K+ rps, a Service Mesh with 1M+ rps, tens of petabytes of data, and production-used machine learning. You will become part of Allegro Tech - We speak at industry conferences, cooperate with tech communities, run our own blog (it's been over 10 years!), record podcasts, lead guilds, and we organize our own internal conference - the Allegro Tech Meeting. We create solutions we love (and can) to talk about! Send us your CV and… see you at Allegro!

🏢 Summary: The offer is for a Project Engineer responsible for coordinating cross-functional teams to deliver AI-powered robotic systems to customers, ensuring end-to-end integration and on-time project execution. The role involves designing robotic station processes, analyzing system performance, and debugging across the full technology stack. It combines technical analysis, project delivery, and frequent collaboration with engineering teams and customer sites. 🗂️ Requirements: Experience in end-to-end project management or similar role, Experience in robotics, intralogistics, or engineering, Ability to analyze performance data and system metrics, Ability to debug complex technical systems across software and hardware, Strong knowledge of data analysis tools (Excel or Google Sheets, SQL), Understanding of full technology stack in robotics systems, Fluent English, Availability to travel up to 40% 📃 Skills: SQL, BigQuery, Grafana, Excel, GoogleSheets, Robotics, Automation, MachineLearning, DataAnalysis, Debugging, Statistics 🏢 Description: Do you love connecting teams to deliver superb value? Are you excited about the delivery of state-of-the-art solutions to customers? Would you like to help us build the AI revolution in robotics? If the answers are yes, then you should keep reading! At Nomagic, we’re on a mission to teach robots the real world. We are looking for a Project Engineer who will ensure the smooth execution of our projects by coordinating work across engineering teams. Offer essentials: Play with robots every day Salary: 24,000 - 29,000 gross UoP per month + equity Relocation package if you are willing to move to Warsaw English-speaking environment Partly remote work is possible! ~Monthly visits to customer sites across Europe Here is why we love this job ourselves, and hope you will enjoy it too: We combine world-class research with top-notch engineering and apply it to solve real problems We build robots and vision systems powered by AI We have them in production at scale and see their real impact on critical operations We are still pretty small, so everyone has a direct impact on the product and how we work Our team has built Google Warsaw, unicorn startups (Climate Corp), tested rocket engines and worked at top companies such as Nvidia or ByteDance. Now we shape the future of smart robotics together! We are scaling our team, product and operations significantly Some of the problems you may try to solve with us: Design the overall process of a robotic station Deliver robots to customers with end-to-end integration from various technical teams (Software, Machine Learning, Mechanical, Electrical, Automation, etc.) Make sure that the deadlines are respected, working with project management from the very beginning of the sales process up to the final acceptance at the customer site Understand the impact and priority of any proposed improvements Analyzes robot performance data using various tools like BigQuery, Grafana, and spreadsheets Deeply understand our technology stack, debug it, analyse system performance and propose improvements Debug issues across the whole stack and make sure they are solved by the right team What skills we’d like you to have: Highly energetic and hands-on attitude! Strive to get things done and find solutions Experience in end-to-end project management or similar role Strong organizational skills and drive to deliver great products on time in full Experience in at least one of the following: robotics industry, intralogistics or engineering experience is required Great analytical skills (Google Sheets / Excel, SQL, basic statistics) Strong decision making skills Excellent communication skills in English, French and/or German is a plus Ability to travel up to 40% (peak) of time to customer sites What should you expect once you apply? 45 minutes Hiring manager Interview 45-minute Data Analytics Interview Onsites - half a day of interviews & discussions at the office Reference check

🏢 Summary: Senior/Expert Java Developer role in an international SaaS project focused on building new AI-driven functionality and modernizing backend systems. The position involves technical ownership, architecture design, and development of scalable microservices-based solutions in a hybrid work model. Candidates will work with Java, Spring Boot, AI technologies, and Microsoft Foundry in a dynamic consultancy environment. 🗂️ Requirements: 8+ years of experience as a Java Developer, Strong knowledge of Java stack, Experience with CI/CD, Experience with Docker, Experience with microservices, Experience building end-to-end solutions, Commercial experience with AI tools, Experience with Microsoft Foundry, Ability to design scalable and maintainable systems, Experience in software house or consultancy environment, Strong understanding of backend architectures, Knowledge of backend development best practices, Strong technical skills, Strong communication skills, Ability to work on multiple projects simultaneously 📃 Skills: Java, Spring, SpringBoot, SQL, Docker, Microservices, CICD, MicrosoftFoundry, AI, Cloud 🏢 Description: Salary: Senior 1000–1300 PLN net / MD Expert/Leader 1300-1600 PLN net / MD (if your financial expectations are higher and justified by your experience, please let us know - we are open to discussing it) Work model: Kraków / Gdańsk  / Warsaw - hybrid work model (2 days per week from the office) Start date: As soon as possible. We can wait up to 1 month if required due to a notice period. Why choose this offer? Real influence on technical decisions and system architecture Dynamic, project-driven environment with diverse challenges Developing new AI-based functionality Project International project focused on building new AI-driven functionality within a modern SaaS platform. This role offers the opportunity to take technical ownership, shape architecture decisions, and contribute to the development of innovative solutions leveraging modern AI technologies, including Microsoft Foundry . Responsibilities you'll have Take technical ownership of the project Design and architect end-to-end backend systems and solutions Supervise and ensure technical quality across projects Support project estimations, including effort, budget, and cost calculations Create and maintain technical designs and documentation Collaborate closely with delivery and business stakeholders Adapt to different client environments, expectations, and technical stacks Work on several projects simultaneously — multitasking is essential Expected competences and knowledge 8+ years of experience as a Java Developer Solid knowledge of the Java stack Solid familiarity with CI/CD , experience working with Docker and microservices Experience in building end-to-end solutions Commercial experience with AI tools Experience with Microsoft Foundry Strong technical and soft skills Proven ability to design scalable and maintainable systems Experience working in a software house / consultancy environment Very good understanding of backend architectures and development best practices Nice to have Experience with cloud platforms (from a developer perspective) Knowledge of modern infrastructure and deployment approaches Technologies you'll work with Java Spring Boot SQL Microsoft Foundry Docker Microservices CI/CD Cloud platforms Client – why choose this particular client from the Jit portfolio? Our client is a leading European SaaS provider specializing in cloud-based solutions for the insurance and pension sector. The cooperation focuses on platform modernization and the development of new AI-based functionality , combining modern technologies with real business impact. About Jit Team The Human Factor of IT - it’s not just a slogan, it’s a philosophy. The foundation of Jit Team is people, which is why we prioritise you. We employ over 770 experienced experts , to whom we offer developmental projects, a wide range of benefits, and a proprietary professional development programme. Together with clients from around the world, we create innovative IT solutions delivered by highly specialised and efficient teams. Behind our maxim are also charitable and educational activities. We support schools, universities, and educational institutions by conducting workshops, running educational projects, sponsoring events, and donating learning equipment. We offer internships that help launch careers in IT. We support water rescuers and hospitals by providing the necessary equipment. We also support numerous charitable organisations helping people in need, children, and the elderly. We are a Polish company and we share what we have achieved over more than 15 years of activity. By supporting local initiatives, we contribute to the circulation of good energy.

🏢 Summary: Fullstack Developer role focused on building and evolving Java-based microservices and modern Angular Single Page Applications within an event-driven architecture. The position emphasizes backend development with Spring Boot, Kafka integration, and secure, scalable solutions, while contributing to CI/CD pipelines and frontend best practices. Work involves close collaboration on solution design, security implementation, and continuous improvement in an Agile environment. 🗂️ Requirements: Strong hands-on experience with Java 17–21, Strong experience with Spring Boot 3.x, Experience with microservices architecture, Experience with Kafka in event-driven or messaging systems, Strong practical experience with SQL and Oracle, Experience or strong understanding of Redis, Experience with Domain Driven Design, Experience with Node.js, Experience with TypeScript, Experience building Single Page Applications with Angular, Strong knowledge of Angular architecture and best practices, Strong understanding of web application security, Practical knowledge of OIDC and OAuth2, Experience with Git, Experience working in Agile methodologies 📃 Skills: Java, Spring, SpringBoot, Microservices, Kafka, SQL, Oracle, Redis, DDD, Node.js, TypeScript, Angular, SPA, Security, OIDC, OAuth2, Git, Agile 🏢 Description: Location: Hybrid work model – 2-3 days per week from the Warsaw office Salary: 160 – 170 PLN net/h (B2B via Experis) Tasks: •    Design, develop, and maintain fullstack applications with a strong emphasis on backend and modern frontend architectures •    Build high-quality, maintainable, secure, scalable, and testable software aligned with business requirements •    Develop and evolve Java-based microservices using Spring Boot •    Contribute to Single Page Applications development ensuring frontend best practices •    Collaborate with business and technical stakeholders to clarify and refine functional and non-functional requirements •    Participate in solution design pre-project studies and technical decision-making •    Integrate systems using event-driven architectures and streaming platforms •    Optimize and maintain existing codebases •    Implement execute and maintain automated tests and CI/CD pipelines •    Ensure application security including identity management and secure authentication flows •    Maintain and update technical documentation •    Participate in internal and external developer communities to share best practices •    Continuously improve skills in modern technologies and software engineering practices Requirements: Backend & Architecture •    Strong hands-on experience with Java 17–21 focusing on modern Java •    Strong experience with Spring Boot 3.x and microservices architectures •    Required experience with Kafka in event-driven or messaging-based systems •    Strong practical experience with SQL using Oracle •    Experience or strong understanding of Redis •    Experience with Domain Driven Design Frontend •    Required experience with Node.js •    Required experience with TypeScript •    Solid experience building Single Page Applications using Angular •    Strong knowledge of Angular best practices architecture and maintainability •    Experience with SPA development •    Webpack knowledge is a nice to have Security •    Strong understanding of web application security •    Practical knowledge of OIDC and OAuth2 protocols •    Experience with identity management platforms as a strong advantage •    Awareness of OWASP principles certifications are a plus DevOps & Tooling •    Required experience with Git •    Experience with CI/CD pipelines GitLab CI and Jenkins as a nice to have •    Maven knowledge as a nice to have •    Docker and Kubernetes knowledge as a nice to have •    Experience with IntelliJ and VS Code •    Knowledge of Jira and Confluence •    Python knowledge as a nice to have •    Practice with AI based code generation tools as a nice to have Methodologies & Ways of Working •    Experience working in Agile methodologies such as Scrum and Kanban •    DevOps mindset and practices •    Ability to collaborate in distributed international teams Offer: •    Multisport card •    Private healthcare •    Access to an e‑learning platform •    Group life insurance

🏢 Summary: Backend Engineer role in the Advertising team focused on building and operating high-availability, large-scale microservices and ML-powered systems. The position involves designing and optimizing distributed systems using a modern cloud-native stack (Kotlin, Spring, Kafka, Kubernetes) and integrating big data and machine learning components into a real-time marketplace. The offer includes hybrid work, competitive salary, annual bonus, and strong ownership within an autonomous agile team. 🗂️ Requirements: Proficiency in Kotlin or Java, Willingness to work with Kotlin in greenfield projects, Experience with backend development and microservices, Ability to design and optimize high-performance, distributed systems, Experience with cloud-native technologies, Understanding of data processing and system integration, English proficiency at B2 level or higher 📃 Skills: Kotlin, Java, Spring, Kafka, Kubernetes, BigQuery, Spark, Docker, Consul, GitHub, GitHubActions, MachineLearning, Microservices 🏢 Description: Important things for you Flexible working hours in the hybrid model (4/1) - working hours start between 7:00 a.m. and 10:00 a.m. We also have 30 days of occasional remote work. The salary range for this position depending on the skill set is as follows (contract of employment, tax-deductible cost): PLN 11 200 - 15 250 Annual bonus based on your annual performance and company results. Our team is based in Poznań. About the job Massive Scale : Design, build, and optimize systems that handle thousands of requests per minute. This is high-availability, high-performance engineering in practice. Modern Tech Stack : Work with a world-class, cloud-native environment. Our core technologies include Kotlin, Spring, Kafka, and Kubernetes. We're not shy when it comes to ML too :) True Ownership & Autonomy : We live by a "you build it, you run it" philosophy. You'll join an agile, autonomous team with full ownership of your microservices, from design to deployment. Complex Challenges : From distributed systems and data streaming to algorithmic optimization, you'll tackle the complex backend problems that power a massive, real-time marketplace. End-to-End ML Systems: Bridge the gap between big data and real-time product impact. You’ll build the infrastructure for serving ML models , using BigQuery and Apache Spark for offline data processing. You’ll integrate these components with our microservices architecture to create the sophisticated advertising system that powers a personalized user experience. Join the Advertising team! You will have a chance to build Allegro Ads - one of the most visible products on the platform. Your team works closely with the Machine Learning team, creating the best experience for customers. High performance, engineering best practices and great atmosphere in the team guaranteed! We are looking for people who: Code in Kotlin or Java and are eager to master Kotlin by taking part greenfield project Want to be proud of the code they create ; they value high-quality code reviews and engage in substantive discussions on software engineering best practices; Are excited about building new products and want to experience the journey of launching a fresh project within the Allegro ecosystem; Are open to developing soft skills and embracing a growth mindset through active participation in code reviews, pair programming, and team retrospectives.; Are open to incorporating AI coding assistants into their daily work to maximize efficiency and focus on complex problem-solving Can look for effective solutions to the requirements set by users; Want to constantly develop and update their knowledge; Know English at at least B2 level. What's in it for you: Well-located offices (with e.g. fully equipped kitchens, bicycle parking, terraces full of greenery) and excellent work tools (e.g., raised desks, ergonomic chairs, interactive conference rooms). A 16" or 14" MacBook Pro or corresponding Dell with Windows (if you don't like Macs) and all the necessary accessories. A wide selection of fringe benefits in a cafeteria plan - you choose what you like (e.g., medical, sports or lunch packages, insurance, purchase vouchers). English classes that we pay for related to the specific nature of your job. A training budget, inter-team tourism ( see more here ), hackathons, and an internal learning platform where you will find multiple trainings. An additional day off for volunteering, which you can use alone, with a team, or with a larger group of people connected by a common goal. Social events for Allegro people - Spin Kilometers, Family Day, Fat Thursday, Advent of Code, and many other occasions we enjoy. And that's just the beginning! You can read more about the benefits here . #goodtobehere means that: You will join a team you can count on - we work with top-class specialists who have knowledge- and experience-sharing in their DNA. You will love our level of autonomy in team organization, the space for continuous development, and the opportunity to try new things. You get to choose which technology solves the problem and you are responsible for what you create. You will value our Developer Experience and the full platform of tools and technologies that make creating software easier. We rely on an internal ecosystem based on self-service and widely used tools such as Kubernetes, Docker, Consul, GitHub, and GitHub Actions. Thanks to this, you can contribute to Allegro from your very first days on the job. You will be equipped with modern AI tools to automate repetitive tasks, allowing you to focus on developing new services and refining existing ones (also leveraging AI support). You will create solutions that will be used (and loved!) by your friends, family and millions of our customers. You will meet the Allegro Scale , which starts with over 1000 microservices, an open-source data bus (Hermes) with 300K+ rps, a Service Mesh with 1M+ rps, tens of petabytes of data, and production-used machine learning. You will become part of Allegro Tech - We speak at industry conferences, cooperate with tech communities, run our own blog (it's been over 10 years!), record podcasts, lead guilds, and we organize our own internal conference - the Allegro Tech Meeting. We create solutions we love (and can) to talk about! Send us your CV and… see you at Allegro!