Sr Full-stack Developer (React, Java)

🏢 Summary: Full-stack Java developer role in the financial sector focused on building scalable microservices and modern frontend applications in an Agile environment. The position involves backend and frontend development using Java, Angular, cloud-native technologies, and distributed systems integrations. Hybrid work model with a long-term international project and competitive B2B rate. 🗂️ Requirements: 5+ years of commercial Java development experience, 2+ years of Angular experience, Knowledge of Spring Framework, Experience with microservices architecture, Experience with Docker, Experience with Kubernetes, Experience with Kafka and distributed systems, Knowledge of REST APIs, Knowledge of SQL, Experience with Oracle databases, Experience with Git, Understanding of Clean Code principles, Understanding of Continuous Integration, Experience integrating REST and SOAP services, Knowledge of XML, Knowledge of JSON, Knowledge of Avro, English level B2 or higher 📃 Skills: Java, Angular, React, Spring, Docker, Kubernetes, Kafka, REST, SQL, Oracle, Git, SOAP, XML, JSON, Avro, Jenkins, ArgoCD 🏢 Description: Senior Java Full-stack Developer 📍 Location: Warsaw, Gdańsk or Gdynia 🏢 Work model: Hybrid (3 days per week in the office) 📅 Project duration: August 2026 – January 2027 💰 B2B rate: up to 157 PLN/h ⏰ Full-time (40h/week) About the project Join an international financial institution and become part of a team responsible for building modern, scalable solutions supporting one of the company's key business domains. You will work in an Agile environment, developing cloud-ready microservices and integrating modern applications with existing enterprise platforms. This role combines backend and frontend development while giving you the opportunity to work with modern technologies, distributed systems, and high-performance applications. Your responsibilities Design, develop and maintain full-stack applications. Build and enhance Java-based microservices. Develop modern frontend solutions using Angular. Integrate applications using REST APIs, Kafka, MQ and Oracle databases. Participate in migration and transformation of existing systems. Ensure application quality, scalability and performance. Collaborate with architects, analysts, QA engineers and business stakeholders. Contribute to code reviews and technical improvements. We are looking for someone who has Minimum 5 years of commercial experience with Java development. At least 2 years of experience with Angular (React is also valued). Strong knowledge of Spring Framework . Experience building microservices architectures . Practical experience with Docker and Kubernetes . Experience working with Kafka and distributed systems. Knowledge of REST APIs , SQL and Oracle databases. Experience with Git . Understanding of Clean Code , Continuous Integration and software engineering best practices. Experience integrating REST and SOAP services. Good understanding of XML, JSON and Avro . Good command of English (B2 or higher) . Nice to have Jenkins Argo CD Event Sourcing Schema Registry DevOps practices What we offer Competitive B2B rate of up to 157 PLN/hour . Long-term international project. Opportunity to work with modern cloud-native technologies. Challenging projects within the financial sector. Professional, collaborative and Agile environment. Work with experienced engineers on large-scale enterprise solutions.

🏢 Summary: Long-term B2B contract for a Java Developer to design, develop and maintain scalable trade booking and control systems for an international financial institution. The role involves building complex integrations, optimizing code and contributing to DevOps and testing processes in a hybrid setup in Warsaw. 🗂️ Requirements: 5+ years of Java development experience, Experience developing complex software systems, Experience with system integration, Experience with code optimisation, Experience with Python or C++, Knowledge of DevOps fundamentals, Knowledge of software testing fundamentals, Understanding of multithreading, Knowledge of messaging systems 📃 Skills: Java, Python, C++, DevOps, Testing, Multithreading, Messaging 🏢 Description: B2B contract via Harvey Nash Duration: long-term (6 months contract cycle) Location: Warsaw (3 days/week onsite) End-client: international financial institution Tasks: Design, develop and maintain scalable solutions for trade booking and control systems and platforms Contribute to DevOps and testing Cooperate with stakeholders Requirements: 5+ years of experience in Java development Experience in developing complex software, integration and code optimisation Experience with other programming languages like Python, C++ Knowledge of DevOps and testing fundamentals Nice to have: experience in finance, fintech or insurance sector, knowledge of multithreading and messaging Fluent in English Allowed to work on B2B in Poland

🏢 Summary: Full Stack Java Developer role focused on enhancing and modernizing legacy Java systems to support ISO 20022, while developing and maintaining backend services in a distributed, event-driven environment. The position involves full lifecycle development, from requirements analysis to production releases, in a hybrid work model in Warsaw. 🗂️ Requirements: 4+ years of experience as Java or Full Stack Developer, Strong experience with Java and Spring ecosystem, Hands-on experience with Hibernate and DB2, Experience with Apache Kafka and event-driven architectures, Experience with MongoDB, Experience building RESTful APIs and microservices, Experience with Maven multi-module builds, Experience with Docker, Experience with Git and CI/CD pipelines, Experience working with distributed systems and legacy codebases 📃 Skills: Java, Spring, SpringBoot, SpringData, SpringSecurity, Hibernate, DB2, Kafka, KafkaStreams, KafkaConnect, MongoDB, REST, Microservices, Maven, Docker, Git, GitLab, CICD, ISO20022 🏢 Description: For our Client we are looking for a Full Stack Java Developer. Warsaw, hybrid (4 days per week from the office) B2B: 28,000–35,000 PLN per month Key Responsibilities Gather and analyse requirements with business stakeholders Design, plan, implement and test changes with the engineering team Adapt and enhance legacy Java applications for ISO 20022 changes Develop and maintain backend services and integrations Participate in code reviews, UAT support and production releases Continuously improve code quality and system design Requirements 4+ years of experience as a Java / Full Stack Developer Strong hands-on experience with: Java, Spring, Spring Boot (DI, Spring Data, Spring Security) Hibernate, DB2 Apache Kafka (producers, consumers, Kafka Streams, Kafka Connect) MongoDB (document modelling, Spring Data MongoDB) RESTful APIs, microservices, event‑driven architectures Maven (multi-module builds) Docker Git & CI/CD (GitLab CI preferred) Experience working in distributed systems and complex legacy codebases Strong analytical skills and ability to understand complex business logic Good communication skills and ability to work in a global team

🏢 Summary: Full Stack Java Developer role focused on enhancing and maintaining legacy Java systems in line with ISO 20022 standards while building and supporting modern backend services and integrations. The position involves working on microservices and event-driven architectures within a distributed environment, contributing to the full development lifecycle from requirements analysis to production releases. 🗂️ Requirements: 4+ years experience as Java or Full Stack Developer, Strong hands-on experience with Java, Strong hands-on experience with Spring and Spring Boot, Experience with Hibernate and DB2, Experience with Apache Kafka, Experience with MongoDB, Experience building RESTful APIs and microservices, Experience with event-driven architectures, Experience with Maven multi-module builds, Experience with Docker, Experience with Git and CI/CD pipelines, Experience working with distributed systems, Experience working with complex legacy codebases 📃 Skills: Java, Spring, SpringBoot, Hibernate, DB2, Kafka, MongoDB, REST, Microservices, Maven, Docker, Git, GitLab, CI/CD 🏢 Description: For our Client we are looking for a Full Stack Java Developer. Warsaw, hybrid (4 days per week from the office) B2B: 28,000–35,000 PLN per month Key Responsibilities Gather and analyse requirements with business stakeholders Design, plan, implement and test changes with the engineering team Adapt and enhance legacy Java applications for ISO 20022 changes Develop and maintain backend services and integrations Participate in code reviews, UAT support and production releases Continuously improve code quality and system design Requirements 4+ years of experience as a Java / Full Stack Developer Strong hands-on experience with: Java, Spring, Spring Boot (DI, Spring Data, Spring Security) Hibernate, DB2 Apache Kafka (producers, consumers, Kafka Streams, Kafka Connect) MongoDB (document modelling, Spring Data MongoDB) RESTful APIs, microservices, event‑driven architectures Maven (multi-module builds) Docker Git & CI/CD (GitLab CI preferred) Experience working in distributed systems and complex legacy codebases Strong analytical skills and ability to understand complex business logic Good communication skills and ability to work in a global team

🏢 Summary: B2B Full Stack Java Developer role in Warsaw (hybrid) focused on enhancing legacy Java systems for ISO 20022 compliance and building backend services and integrations. The position involves designing, implementing and testing changes in distributed, event‑driven architectures while collaborating with business stakeholders and global teams. Emphasis is placed on code quality, system design and production support. 🗂️ Requirements: 4+ years experience as Java or Full Stack Developer, Strong hands-on experience with Java, Strong hands-on experience with Spring and Spring Boot, Experience with Hibernate and DB2, Experience with Apache Kafka, Experience with MongoDB, Experience building RESTful APIs and microservices, Experience with event-driven architectures, Experience with Maven multi-module builds, Experience with Docker, Experience with Git and CI/CD, Experience working with distributed systems, Experience working with complex legacy codebases 📃 Skills: Java, Spring, SpringBoot, Hibernate, DB2, Kafka, MongoDB, REST, Microservices, Maven, Docker, Git, GitLab, CI/CD 🏢 Description: For our Client we are looking for a Full Stack Java Developer. Warsaw, hybrid (4 days per week from the office) B2B: 28,000–32,000 PLN per month Your responsibilities Gather and analyse requirements with business stakeholders Design, plan, implement and test changes with the engineering team Adapt and enhance legacy Java applications for ISO 20022 changes Develop and maintain backend services and integrations Participate in code reviews, UAT support and production releases Continuously improve code quality and system design Requirements: 4+ years of experience as a Java / Full Stack Developer Strong hands-on experience with: Java, Spring, Spring Boot (DI, Spring Data, Spring Security) Hibernate, DB2 Apache Kafka (producers, consumers, Kafka Streams, Kafka Connect) MongoDB (document modelling, Spring Data MongoDB) RESTful APIs, microservices, event‑driven architectures Maven (multi-module builds) Docker Git & CI/CD (GitLab CI preferred) Experience working in distributed systems and complex legacy codebases Strong analytical skills and ability to understand complex business logic Good communication skills and ability to work in a global team

🏢 Summary: B2B contract opportunity for a Full Stack Developer focused on Java, React, and cloud-native technologies to build advanced planning applications and scalable backend/frontend systems. The role involves AI-assisted development, CI/CD ownership, automated testing, and collaboration with cross-functional product teams in a mostly remote setup. 🗂️ Requirements: Strong proficiency in React, Strong proficiency in Next.js, Strong proficiency in Node.js, Experience with Server-Side Rendering (SSR), Advanced programming experience with Java, Advanced programming experience with TypeScript, Deep knowledge of Java enterprise development, Experience with Spring Boot, Experience integrating LLMs and AI tools, Experience with REST APIs, Experience with relational databases, Experience with NoSQL databases, Experience with MS Azure, Hands-on experience with Docker, Hands-on experience with Kubernetes, Hands-on experience with Terraform, Experience with GitHub Actions, Experience with Gradle, Experience writing Unit tests, Experience writing Integration tests, Experience writing E2E tests, English proficiency minimum B2, Polish proficiency minimum B2+, Understanding of Agile principles, Knowledge of Scrum or Kanban 📃 Skills: Java, React, Next.js, Node.js, TypeScript, JavaScript, Spring, SpringBoot, REST, SQL, NoSQL, Azure, Docker, Kubernetes, Terraform, GitHub, Actions, Gradle, SSR, LLM, AI, Scrum, Kanban 🏢 Description: For one of our clients, we are looking for a Full Stack Developer (Java,React). Offer • Rate: up to 140 PLN/h net+VAT • Location: remote + visits in Katowice once per quarter • Contract: B2B Requirements • Strong proficiency in React, Next.js, and Node.js , including Server-Side Rendering (SSR) . Vue is a plus. • Advanced, hands-on programming experience with both Java and TypeScript / JavaScript. • Deep knowledge of enterprise software development using Java and Spring Boot technologies. • Experience integrating LLMs and AI tools into daily workflows to optimize development speed. • Mastery of REST APIs and experience with r elational/NoSQL databases , especially within MS Azure . • Hands-on experience with Docker, Kubernetes, Terraform , and pipeline automation via GitHub Actions and Gradle. • Direct experience writing automated Unit, Integration, and E2E tests. • Proficiency in English at a B2 minimum level. • Proficiency in Polish at a B2+ minimum level. • Strong understanding of Agile principles including Scrum or Kanban. Responsibilities • Design advanced planning applications in close collaboration with cross-functional teams. • Develop robust backend APIs for resource scheduling, allocation logic, and core modules. • Create responsive interfaces focused on performance, security, data visualization, and accessibility. • Build your own AI-based work environment using advanced developer tools to maximize efficiency. • Manage the platform lifecycle from architectural strategy to operations and CI/CD practices. • Design and implement automated test scenarios to guarantee platform success. • Maintain active communication with the Technical Product Owner and Product Management organization to align priorities.

🏢 Summary: Full-time hybrid contract for an experienced Python Fullstack Developer working on AI-driven automation and data transformation solutions in the financial sector. The role involves building scalable full-stack applications, REST APIs, microservices, and LLM-based solutions using Python, Flask, and React in an Agile international team. 🗂️ Requirements: Strong commercial experience with Python, Experience with Flask or similar Python frameworks, Knowledge of REST API development, Experience with Large Language Models, Experience with Docker, Knowledge of JavaScript, Experience with React, Understanding of PostgreSQL, SQL and SQLAlchemy, Experience writing automated tests with pytest, Experience with CI/CD pipelines, Knowledge of Git, English level B2/C1 📃 Skills: Python, Flask, REST, LLM, Docker, JavaScript, React, PostgreSQL, SQL, SQLAlchemy, pytest, CI/CD, Git, TypeScript, Redux, Zustand, AWS, Kubernetes, SharePoint, JFrog, CSS, SCSS 🏢 Description: Expert Python Fullstack Developer 📍 Location: Warsaw 🏢 Work model: Hybrid (3 days per week in the office) 📅 Project duration: July 2026 – December 2026 💰 B2B rate: up to 142 PLN/h ⏰ Full-time (40h/week) About the project We are looking for an experienced Python Fullstack Developer to join an international team delivering innovative solutions for the financial sector. The project focuses on data transformation, AI-driven automation, and intelligent data enrichment , leveraging modern technologies including Large Language Models (LLMs) to improve operational efficiency and regulatory compliance. You will work closely with Product Owners, Architects, Analysts and other developers to transform business requirements into scalable, secure and high-quality software solutions. Your responsibilities Design, develop and maintain modern full-stack applications. Build backend services using Python and Flask . Develop and maintain REST APIs and data integration services. Implement AI-powered solutions using LLMs for automation and data enrichment. Develop frontend components using React and JavaScript. Build microservices and deployment pipelines. Integrate with databases, external APIs and enterprise platforms. Ensure data quality, reconciliation and regulatory compliance. Write automated tests and participate in code reviews. Collaborate with cross-functional, international teams in an Agile environment. We are looking for someone who has Strong commercial experience with Python development. Hands-on experience with Flask (or similar Python frameworks). Solid knowledge of REST API development. Experience working with Large Language Models (LLMs) . Experience with Docker . Good knowledge of JavaScript . Experience with React . Good understanding of PostgreSQL , SQL and SQLAlchemy . Experience writing automated tests (preferably using pytest ). Experience with CI/CD pipelines . Good knowledge of Git . Good command of English (B2/C1) . Nice to have AI development tools and frameworks. TypeScript. Redux or Zustand. AWS Cloud. Kubernetes. SharePoint API. JFrog Artifactory. Web Components. CSS / SCSS. What we offer B2B rate of up to 142 PLN/hour . Opportunity to work on innovative AI and data-driven solutions within the banking sector. International and collaborative Agile environment. Exposure to modern technologies including LLMs , cloud solutions and microservices. Challenging project with real business impact. Long-term cooperation with experienced engineering team

🏢 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: Full Stack Engineer role focused on building and owning integrations between enterprise HR systems and third-party SaaS platforms in a cloud-native environment. The position involves backend-heavy development, API design, CI/CD implementation, and collaboration with HR, Finance, and security teams. Hybrid work model in Warsaw with competitive monthly salary. 🗂️ Requirements: 5+ years of software engineering experience, Experience with SaaS HR software integrations, Knowledge of backend programming languages, Knowledge of JavaScript or TypeScript, Experience designing and implementing RESTful APIs, Experience integrating third-party web services, Knowledge of OAuth2, OIDC, SAML and SSO, Experience with AWS or another major cloud platform, Experience with Git, Experience with CI/CD pipelines, Experience with Terraform, Frontend development experience, Experience gathering and managing requirements, Fluent English 📃 Skills: Java, Python, JavaScript, TypeScript, REST, SOAP, OAuth2, OIDC, SAML, SSO, AWS, Git, CI/CD, Terraform, API 🏢 Description: For our client, an international financial company, we are looking for: Full Stack Engineer, HR Enterprise Systems Location: Warsaw, Poland (3 days in office per week) Salary: 28 000 – 38 000 PLN gross / month (employment) Tasks: Build and own integrations between enterprise systems and third-party HR SaaS platforms (70% backend, 30% frontend) Lead end-to-end technical delivery of integration projects Design and implement robust RESTful APIs and web service adapters that handle both modern REST and legacy SOAP interfaces Partner with HR, Talent Acquisition, Finance and other corporate teams to gather and manager requirements Act as the cloud-native integration owner with security and compliance teams Implement and maintain CI/CD pipelines, automated tests and monitoring Requirements: 5+ years of experience in software engineering (development & design) Hands-on experience in SaaS HR software integration (preferably in-house) Knowledge of one of major backend languages and also JavaScript or TypeScript (preferred stack: Java, Python, JS) Proven experience designing and implementing RESTful APIs and integrating third-party web services Experience with authentication and authorization standards (OAuth2, OIDC, SAML and SSO) Experience building and operating services on a major cloud platform (AWS preferred) Experience with Git, CI/CD and IaC (Terraform) Some experience with frontend development Some experience in gathering and managing requirements (liaising with stakeholders) Fluent in English

🏢 Summary: Senior Java Full-Stack Developer role for international projects, focused on end-to-end development of web applications in a cloud-based environment. The position involves backend and frontend development, design and testing activities, and collaboration within agile teams. It is a fully remote B2B contract with long-term cooperation. 🗂️ Requirements: Bachelor’s degree in Engineering, IT, Science, or related technical field, Minimum 5 years of commercial experience in corporate IT, Strong experience with Java and Java frameworks, Commercial experience with frontend technologies, Solid knowledge of JavaScript, HTML5, CSS3, Experience with Angular, Knowledge of databases and SQL, Experience with REST and SOAP web services, Experience with AWS or Azure, Knowledge of Clean Code principles, Experience with unit testing, Experience with source code management, Experience with CI/CD and automated deployments, Very good English (spoken and written), Experience in agile (Scrum) environments 📃 Skills: Java, Spring, JavaScript, HTML5, CSS3, Angular, SQL, REST, SOAP, AWS, Azure, CI/CD, Git, Scrum 🏢 Description: Senior Java Full-Stack Developer – Remote Contract type: B2B Hourly rate: 160–170 PLN/h Location: Remote We are looking for an experienced Senior Java Full-Stack Developer to join international implementation projects. The role involves end-to-end development of web applications, close collaboration with agile teams, and active participation in design and testing activities. The position is well suited for a developer who values clean code, quality, and teamwork in a cloud-based environment. Responsibilities Work as a Senior Java Full-Stack Developer across multiple implementation streams Develop and maintain web-based applications using Java and modern frontend technologies Write and maintain unit tests to ensure software quality Collaborate with agile team members to achieve project and client goals Participate in design reviews, testing activities, and technical discussions Requirements Bachelor’s degree in Engineering, IT, Science, or another technical field Minimum 5 years of commercial experience in a corporate IT environment Strong experience with Java and commonly used Java frameworks Commercial experience with frontend technologies and web-based applications Solid knowledge of JavaScript, HTML5, CSS3, and responsive single-page application design Experience with Angular Knowledge of databases and SQL Experience with web services and APIs (REST, SOAP) Experience deploying applications on cloud platforms such as AWS or Azure Knowledge of Clean Code principles and unit testing Experience with source code management, CI/CD, and automated deployments Very good English, both spoken and written Experience working in international and agile (Scrum) environments Strong communication and collaboration skills Nice to have Experience with Kafka or RabbitMQ Hands-on experience with microservices architecture Knowledge of Docker and Kubernetes Relevant certifications (Java, Spring, SQL, AWS, Azure) Knowledge of German or another European language Benefits Medicover healthcare package Multisport card Access to an e-learning platform Group life insurance We offer Fully remote cooperation Competitive hourly rate: 160–170 PLN/h (B2B) Long-term cooperation in international projects Modern technology stack and agile working environment