Senior Java Developer

🏢 Summary: Senior Backend Engineer role for a 3-month modernization project focused on upgrading Java and Scala backend services, migrating authentication systems to OAuth, and building large-scale Spark data pipelines. The position requires hybrid work in Warsaw or Kraków, with a fully covered onboarding period in Sweden. 🗂️ Requirements: 5+ years commercial backend experience, Strong production experience with Java, Strong production experience with Scala, Experience with Play Framework or Akka/Pekko, Hands-on experience with Spark, Experience with OAuth authentication, Professional English proficiency, Availability for 2-week onboarding in Sweden, Hybrid availability in Warsaw or Kraków office 3 days/week 📃 Skills: Java, Scala, Play, Akka, Pekko, Spark, OAuth, React, TypeScript, CI/CD, Gradle 🏢 Description: Senior Backend Engineer (Scala / Java) – 3-Month Project Salary: Up to 175 PLN/h net + VAT (B2B Contract) Location: Hybrid – Warsaw or Kraków (strictly 3 days/week from the office – non-negotiable) Onboarding: 2 weeks on-site in Malmö, Sweden (fully covered) Project Duration: 3 months Start Date: ASAP/Beginning of August at the absolute latest About the Project An innovative technology-sector project focused on modernizing and optimizing core backend services, streamlining data pipelines, and enhancing system security. This is a highly autonomous role requiring a seasoned engineer who can quickly adapt to a complex ecosystem, utilize automation tools for framework upgrades, and manage extensive data migration tasks. Key Responsibilities - Modernize and refactor backend services by upgrading legacy Java and Scala-based frameworks. - Leverage automation and modern tooling to accelerate code transformations, dependency resolution, and compatibility fixes. - Migrate legacy authentication mechanisms across services to secure OAuth-based solutions. - Consolidate multiple data stores into unified, versioned tables using heavy Spark/Java batch pipelines. Requirements - Minimum 5 years of commercial backend experience (7+ years preferred). - Deep production experience with Java and Scala. - Strong familiarity with Play Framework or Akka/Pekko. - Hands-on experience with Spark for complex data pipeline processing. - Practical experience with OAuth authentication patterns. - Excellent communication skills and full professional English proficiency. - Full availability for a 2-week onboarding trip to Sweden at the beginning of the contract. Nice to Have - Basic exposure to React or TypeScript. - Familiarity with CI/CD pipelines, Gradle, and scripting. What We Offer - Transparent and quick 2-stage recruitment process. - Attractive hourly rate with seamless B2B invoicing. - Opportunity to work on a high-exposure architectural modernization project for an international client.

🏢 Summary: Backend Developer role focused on modernizing and optimizing backend services and data pipelines, including technology upgrades, authentication migration, and automation initiatives. The position involves working with Java/Scala ecosystems, Spark pipelines, and OAuth-based security in a hybrid model with onboarding in Sweden. B2B contract with competitive hourly rate and English as the project language. 🗂️ Requirements: Hands-on experience with production Java services, Hands-on experience with production Scala services, Familiarity with Play Framework internals, Experience with Spark for data pipelines, Experience with OAuth-based authentication patterns, Availability for hybrid work (3 days/week in Warsaw or Cracow), Availability for 2-week onboarding in Malmo, Sweden, Fluent English 📃 Skills: Java, Scala, Play, Spark, OAuth, Gradle, CI/CD, React, TypeScript 🏢 Description: 🌍 Work mode: hybrid –  3 days from the Warsaw OR Cracow office. ⏳ Duration : > 3 months contracts . 🔍 Onboarding : 2 weeks in Malmo, Sweden. ⏰ Start : August 3rd at the latest. 📝 Contract : B2B > up 200 zl/h. ⚙️ Recruitment process : 2 meetings. 📕Project language : English. 💼 Industry : Technology. 💻 Workload : Full time (40 hours per week). Summary: The Backend Developer role is aimed at enhancing and modernizing backend services and pipelines within the organization. This position primarily focuses on improving system performance, ensuring robust authentication mechanisms, and implementing automation to streamline processes. Main Responsibilities: Modernise backend services and pipelines by upgrading to the latest JDK, Scala 3.x, and Play Framework 3.x. Apply GenAI tooling to automate code transformations, dependency resolution, and compatibility fixes, producing reusable tools and documentation. Migrate authentication frameworks from legacy APIs to OAuth-based solutions across various backend services. Replace multiple data stores with a single versioned table, creating Spark/Java batch pipelines for backfill/migration and extending Scala/Play backends. Key Requirements: Hands-on experience with production Java/Scala services . Familiarity with Play Framework internals. Experience with Spark for pipeline-heavy work. Comfortable with OAuth-based authentication patterns. Nice to Have: Familiarity with React/TypeScript. For DevOps-leaning candidates: experience with Gradle, scripting, and CI/CD pipelines. Other Details Tools/Methodologies: Java, Scala, Play Framework, Spark, OAuth.

🏢 Summary: Backend Developer role focused on modernizing and optimizing backend services and data pipelines, including migration to newer Java/Scala and Play Framework versions and implementation of OAuth-based authentication. The position involves automation with GenAI tools and Spark-based data migrations in a hybrid work model. B2B contract with onboarding in Sweden and full-time engagement in English. 🗂️ Requirements: Hands-on experience with production Java services, Hands-on experience with production Scala services, Experience with Play Framework internals, Experience with Spark for pipeline-heavy work, Experience with OAuth-based authentication patterns, Availability to work hybrid from Warsaw or Cracow office, Availability for 2-week onboarding in Malmo, Sweden, Fluency in English 📃 Skills: Java, Scala, Play, Spark, OAuth, JDK, GenAI, Gradle, CI/CD, React, TypeScript 🏢 Description: 🌍 Work mode: hybrid –  3 days from the Warsaw OR Cracow office. ⏳ Duration : > 3 months contracts . 🔍 Onboarding : 2 weeks in Malmo, Sweden. ⏰ Start : August 3rd at the latest. 📝 Contract : B2B > up 195 zl/h. ⚙️ Recruitment process : 2 meetings. 📕Project language : English. 💼 Industry : Technology. 💻 Workload : Full time (40 hours per week). Summary: The Backend Developer role is aimed at enhancing and modernizing backend services and pipelines within the organization. This position primarily focuses on improving system performance, ensuring robust authentication mechanisms, and implementing automation to streamline processes. Main Responsibilities: Modernise backend services and pipelines by upgrading to the latest JDK, Scala 3.x, and Play Framework 3.x. Apply GenAI tooling to automate code transformations, dependency resolution, and compatibility fixes, producing reusable tools and documentation. Migrate authentication frameworks from legacy APIs to OAuth-based solutions across various backend services. Replace multiple data stores with a single versioned table, creating Spark/Java batch pipelines for backfill/migration and extending Scala/Play backends. Key Requirements: Hands-on experience with production Java/Scala services . Familiarity with Play Framework internals. Experience with Spark for pipeline-heavy work. Comfortable with OAuth-based authentication patterns. Nice to Have: Familiarity with React/TypeScript. For DevOps-leaning candidates: experience with Gradle, scripting, and CI/CD pipelines. Other Details: Tools/Methodologies: Java, Scala, Play Framework, Spark, OAuth.

🏢 Summary: Hybrid Backend Developer role focused on modernizing and optimizing backend services, upgrading core technologies, and improving authentication and data pipelines. The project involves Java/Scala development, Play Framework upgrades, Spark-based batch processing, and OAuth migration. B2B contract with fast recruitment process and onboarding in Sweden. 🗂️ Requirements: Hands-on experience with production Java services, Hands-on experience with production Scala services, Familiarity with Play Framework internals, Experience with Spark for pipeline-heavy work, Experience with OAuth-based authentication patterns, Fluent English for project communication 📃 Skills: Java, Scala, Play, Spark, OAuth, JDK, GenAI, Gradle, CI/CD, React, TypeScript 🏢 Description: 🌍 Work mode: hybrid –  3 days from the Warsaw office. 🔍 Onboarding : 2 weeks in Malmo, Sweden. ⏰ Start : 1 week notice period, August 3rd at the latest. 📝 Contract : B2B > up 195 zl/h. ⚙️ Recruitment process : 1 meeting with the client. ⏳ Duration : > 3 months contracts + extensions. 📕Project language : English. 💼 Industry : Technology. 💻 Workload : Full time (40 hours per week). Summary: The Backend Developer role is aimed at enhancing and modernizing backend services and pipelines within the organization. This position primarily focuses on improving system performance, ensuring robust authentication mechanisms, and implementing automation to streamline processes. Main Responsibilities: Modernise backend services and pipelines by upgrading to the latest JDK, Scala 3.x, and Play Framework 3.x. Apply GenAI tooling to automate code transformations, dependency resolution, and compatibility fixes, producing reusable tools and documentation. Migrate authentication frameworks from legacy APIs to OAuth-based solutions across various backend services. Replace multiple data stores with a single versioned table, creating Spark/Java batch pipelines for backfill/migration and extending Scala/Play backends. Key Requirements: Hands-on experience with production Java/Scala services . Familiarity with Play Framework internals. Experience with Spark for pipeline-heavy work. Comfortable with OAuth-based authentication patterns. Nice to Have: Familiarity with React/TypeScript. For DevOps-leaning candidates: experience with Gradle, scripting, and CI/CD pipelines. Other Details Tools/Methodologies: Java, Scala, Play Framework, Spark, OAuth.

🏢 Summary: Senior Full Stack Developer role for an international product team focused on building scalable applications using TypeScript, React, Node.js, PostgreSQL, and Kafka. The contract is remote, B2B, initially for 6 months with possible extension, and includes collaboration in an agile international environment with AI-powered development tools. 🗂️ Requirements: 8+ years of commercial software development experience, Strong TypeScript experience, Experience with React, Experience with Node.js, Experience with NestJS, Knowledge of PostgreSQL, Knowledge of REST APIs, Knowledge of Kafka, Experience building scalable systems, Daily use of AI coding tools, English level B2+/C1 📃 Skills: TypeScript, React, Node.js, NestJS, PostgreSQL, REST, Kafka, Claude, Cursor, Codex, Copilot 🏢 Description: Senior Full Stack Developer (TypeScript / React / Node.js) Contract: B2B Rate: Up to 150–160 PLN/hour Duration: 6 months with a strong possibility of extension Start: ASAP About the project We are looking for an experienced Senior Full Stack Developer to join an international product development team. You will work on building and enhancing scalable software solutions in a modern technology stack, collaborating with experienced engineers in an agile environment. Your responsibilities - Design, develop, and maintain scalable full stack applications. - Build high-quality backend services and modern frontend solutions. - Develop and integrate REST APIs. - Work with PostgreSQL and Kafka-based architectures. - Collaborate with cross-functional, international teams. - Apply AI-powered coding tools to improve development efficiency and code quality. Requirements - 8+ years of commercial software development experience. - Strong experience with TypeScript on both the frontend and backend. - Hands-on experience with React and Node.js/NestJS. - Solid knowledge of PostgreSQL, REST APIs, and Kafka. - Experience designing and building scalable systems or software products. - Daily use of AI coding tools such as Claude Code, Cursor, Codex, GitHub Copilot, or similar (must have). - Very good English communication skills (B2+/C1, must have). Nice to have - Experience building SaaS products. - Experience developing on-premise software solutions. Recruitment process The recruitment process includes a technical assignment (approximately 5 hours). During the task, you are welcome and encouraged to use AI coding tools, as we value modern software development practices.

🏢 Summary: Full Stack Engineer role in the banking sector focused on delivering production-ready solutions within a scalable microservices architecture. The position combines backend application design and frontend development, emphasizing RESTful APIs, PostgreSQL databases, and automated CI/CD pipelines. This is a long-term B2B engagement with a hybrid work model and collaboration across global engineering teams. 🗂️ Requirements: Proven commercial experience in backend application design and enterprise deployment, Strong experience working within microservices architecture, Hands-on experience building and deploying RESTful APIs, Strong proficiency in PostgreSQL schema design and querying, Experience supporting automated CI/CD production releases, Full professional English proficiency 📃 Skills: Java, ReactJS, PostgreSQL, REST, Microservices, CI/CD, Docker, Kubernetes, GCP 🏢 Description: co.brick talents — powered by AI, powered by people. Join a global engineering team within the banking sector focused on delivering high-quality production code through a scalable microservices architecture. In this Full Stack role, you will balance backend application design and frontend development while fostering a modern, high-performing engineering culture. You will collaborate across regional boundaries, address technical risks, and drive automated deployment practices to push changes to production frequently. Details Engagement Details Contract Type: B2B Allocation: Full-time workload. Start Date: ASAP / 1-month notice period acceptable. Duration: Long-term (> 12 months). Work Model: Hybrid – 6 days per month required in the Kraków office (flexible scheduling, including the option to complete all 6 days in a single block). Recruitment Process: 2 rounds (Technical Interview & Live Coding). Responsibilities Hands-on Delivery: Write, review, and ship production-ready full-stack code aligned with a distributed microservices structure. API & Database Engineering: Design, develop, and deploy robust RESTful APIs and write schemas for relational databases. Cross-Functional Collaboration: Partner with a global engineering and business network, removing delivery impediments and proactively flagging risks to program management. Process Optimization: Monitor business, engineering, and non-functional project requirements to eliminate technical debt and process inefficiencies. Requirements Senior Engineering Baseline: Proven commercial track record in backend application design, development, and enterprise deployment. Architecture: Strong experience implementing and maintaining code within a microservices ecosystem. CI/CD Mindset: Demonstrated ability to support frequent, automated production releases. API Development: Extensive hands-on experience building and deploying RESTful APIs. Database Skills: Strong proficiency in schema design and querying within PostgreSQL databases. Languages: Full professional English proficiency (the sole project language). Nice to Have Solid experience with Java , preferably using recent versions of the language. Practical familiarity with frontend development using ReactJS . Understanding of cloud-native systems, containerization, and orchestration technologies ( Docker, Kubernetes, and GCP ). Prior domain experience working within the financial or fintech/banking sector. Polish B2+

🏢 Summary: Backend Engineer role focused on building scalable backend systems, APIs, and data processing solutions for a global developer platform used by millions of users. The position involves working with distributed systems and large datasets in an international environment, with initial on-site work in Malmö followed by relocation to Sweden. Offers competitive B2B rates and the opportunity to contribute end-to-end from architecture discussions to production deployment. 🗂️ Requirements: Commercial experience in backend development, Strong knowledge of Java, Strong knowledge of Scala, Experience with Apache Spark, Experience with distributed systems, Experience building and maintaining APIs, Ability to design scalable backend architectures, Experience with data processing pipelines, Experience with CI/CD processes, Ability to work on-site in Malmö and relocate to Sweden 📃 Skills: Java, Scala, Spark, Apache, DistributedSystems, APIs, CI/CD, Backend, DataProcessing 🏢 Description: Salary: Mid Developer : up to 1120 PLN/MD on B2B Senior Developer : up to 1500 PLN/MD on B2B Work model: hybrid , for the first 3-4 months required 3 days/week on-site in Malmö (Sweden), with travel and accommodation covered by the company, followed by relocation to Sweden with a requirement to work 3-5 days per week from the office, along with a rate evaluation after relocation. Why choose this offer? Opportunity to work on global-scale products used by millions of users worldwide Collaboration within international, cross-functional teams Exposure to modern backend technologies (Scala, Java, Spark) Chance to build scalable APIs and developer-facing tools Impact on end-to-end feature development – from concept to production Work in an environment that values ownership, independence, and collaboration Project You will join a team working on a developer platform powering advanced digital products and services. The role focuses on building scalable backend solutions, APIs, and tools that support large-scale applications and external developers. As a Backend Engineer, you will contribute to designing and implementing distributed systems, processing large datasets, and enabling seamless integration between services. You will collaborate closely with engineering, data, and product teams to deliver high-quality solutions used in a global ecosystem. The role combines hands-on development with active participation in architecture discussions , problem-solving , and cross-team collaboration . Responsibilities you'll have: Design, develop and maintain scalable backend systems and services Build and optimize data processing pipelines using tools such as Apache Spark Develop and maintain APIs and backend components for developer-facing platforms Translate business and technical requirements into robust, high-quality code Collaborate with cross-functional and international teams (engineering, product, data) Participate in architecture discussions and propose improvements to system design Ensure performance, reliability, and scalability of delivered solutions Contribute to code reviews, testing, and CI/CD processes Work both independently and collaboratively to solve complex technical problems Technologies you'll work with Java Scala Apache Spark GIS/Mapping Technologies Distributed systems & data processing API design & backend architecture Client – why choose this particular client from the Jit portfolio? Our client is a leading multinational technology organization with a strong international presence. Serving customers worldwide, it offers a broad range of consumer electronics, software, and digital solutions aimed at enhancing user experience and connectivity. The organization is renowned for its innovative approach and its ability to create a seamless ecosystem that integrates its products and services. 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: Hybrid Backend Engineer role focused on building scalable distributed systems, APIs, and data processing pipelines for a global developer platform. The position involves working with Java, Scala, and Apache Spark on large-scale products used worldwide, with relocation to Sweden required. The role combines hands-on development, architecture discussions, and cross-functional collaboration. 🗂️ Requirements: Commercial experience in backend development, Strong knowledge of Java, Strong knowledge of Scala, Experience with Apache Spark, Experience building distributed systems, Experience designing and developing APIs, Ability to work on-site in Malmö (3–4 days/week initially), Willingness to relocate to Sweden, Experience with data processing pipelines, Experience with CI/CD and code reviews 📃 Skills: Java, Scala, Spark, API, CI/CD, DistributedSystems, DataProcessing 🏢 Description: Salary: Mid Developer: up to 1120 PLN/MD on B2B Senior Developer: up to 1500 PLN/MD on B2B Work model: Hybrid – for the first 3–4 months required 3 days/week on-site in Malmö (Sweden), with travel and accommodation covered by the company, followed by relocation to Sweden with a requirement to work 3–5 days per week from the office, along with a rate evaluation after relocation. Why choose this offer? - Opportunity to work on global-scale products used by millions of users worldwide - Collaboration within international, cross-functional teams - Exposure to modern backend technologies (Scala, Java, Spark) - Chance to build scalable APIs and developer-facing tools - Impact on end-to-end feature development – from concept to production - Work in an environment that values ownership, independence, and collaboration Project You will join a team working on a developer platform powering advanced digital products and services. The role focuses on building scalable backend solutions, APIs, and tools that support large-scale applications and external developers. As a Backend Engineer, you will contribute to designing and implementing distributed systems, processing large datasets, and enabling seamless integration between services. You will collaborate closely with engineering, data, and product teams to deliver high-quality solutions used in a global ecosystem. The role combines hands-on development with active participation in architecture discussions, problem-solving, and cross-team collaboration. Responsibilities: - Design, develop and maintain scalable backend systems and services - Build and optimize data processing pipelines using tools such as Apache Spark - Develop and maintain APIs and backend components for developer-facing platforms - Translate business and technical requirements into robust, high-quality code - Collaborate with cross-functional and international teams (engineering, product, data) - Participate in architecture discussions and propose improvements to system design - Ensure performance, reliability, and scalability of delivered solutions - Contribute to code reviews, testing, and CI/CD processes - Work both independently and collaboratively to solve complex technical problems Technologies: - Java - Scala - Apache Spark - Distributed systems - Data processing - API design - Backend architecture

🏢 Summary: Backend Developer role focused on designing and building scalable, secure microservices and APIs using Java and Spring Boot in a cloud-oriented environment. The position emphasizes strong data modeling, architecture design, and CI/CD-driven delivery within Agile teams. The contractor will develop resilient backend solutions and ensure high code quality and reliability. 🗂️ Requirements: Hands-on experience with API and Microservices development in Java or Spring Boot, Proficiency in Java/J2EE application development, Experience with Spring Framework and Hibernate JPA, Experience building and consuming REST web services, Experience working with XML and JSON, Experience with relational or NoSQL databases (Oracle, PostgreSQL, MongoDB), Experience with CI/CD pipelines and Jenkins, Experience with Docker and Git, Unix proficiency, Experience working in Agile methodologies (Scrum or Kanban) 📃 Skills: Java, Spring, SpringBoot, J2EE, Hibernate, JPA, REST, XML, JSON, Oracle, PostgreSQL, MongoDB, Jenkins, Docker, Git, Unix, CICD, Microservices, Agile, Scrum, Kanban 🏢 Description: Location : Cracow Mode : Hybrid (6 days per month at the office - flexible) Contract : B2B Rate : 160-170 PLN/h Introduction & Summary We are seeking a skilled Backend Developer who possesses a deep knowledge of data modeling and architecture. The ideal candidate should have extensive experience in API development using core Java and Spring Boot, with a strong grasp of security principles and Agile methodologies. The role requires an analytical mindset, capable of designing resilient and scalable solutions while working cross-functionally to foster collaboration and innovation. Main Responsibilities Ensure proper definition and architecture of non-functional requirements in design. Develop and grow skills in designing cloud-based, secure, and adaptable solutions. Build scalable, highly reliable product features through effective software design and implementation. Apply problem-solving and analytical skills to diverse challenges. Interact with cross-functional teams for scalable solution production. Estimate engineering efforts and develop realistic schedules. Identify and resolve complex production issues efficiently. Conduct comprehensive design and code reviews and perform unit testing. Utilize source control and bug tracking systems responsibly. Key Requirements Hands-on experience in API and Microservices development using core Java and/or Spring Boot . Proficient in application development using Java/J2EE and related technologies, including Spring Framework and Hibernate JPA. Experience in developing reusable APIs and consuming web services (REST), as well as processing data formats like XML/JSON. Expert knowledge of Agile/Scrum/Kanban development methodologies and experience with databases (Oracle, Postgre, MongoDB). Extensive knowledge of CI/CD deployment pipelines, including Jenkins, Docker, shell scripting, and GIT with Unix proficiency. Nice to Have Experience in JavaScript frameworks such as ReactJs, Node JS, Angular, and jQuery. Familiarity with JavaScript build tools and dependency management. Experience in creating responsive designs using frameworks like Bootstrap. Knowledge of GCP, GKE, AWS is an advantage. Experience or knowledge in system architecture and solution design. Hands-on experience in Python, Machine Learning, and Data Science.

🏢 Summary: Senior Backend Engineer role focused on modernising legacy Java services and delivering scalable microservices, with strong emphasis on hands-on coding and AI-assisted development. The position involves improving performance, reliability, and CI/CD processes while shipping production-ready solutions. It targets experienced engineers who can drive service modernisation at scale. 🗂️ Requirements: 8+ years of backend engineering experience, Strong expertise in Java, Experience with microservices architecture, Proven experience modernising production systems at scale, Solid knowledge of API design, Strong understanding of distributed systems, Hands-on coding experience, Experience with AI developer tools 📃 Skills: Java, Microservices, APIs, DistributedSystems, CI/CD, Copilot, LLM, Automation 🏢 Description: Location : Kraków, Hybrid 3days/office OR remote Employment type : permanent - UoP Salary: up 30000zł/month Senior Backend Engineer – Service Modernisation & AI Enablement You’ll join a small, senior team working hands-on to modernise critical backend services and improve delivery speed. The role is highly practical, focused on shipping production-ready solutions and using AI as an accelerator. What You’ll Do Modernise legacy Java services using proven migration patterns Analyse existing codebases, dependencies, and APIs, leveraging AI tools where helpful Design and deliver scalable, reliable microservices with strong test coverage and documentation Improve performance, reliability, and API responsiveness with measurable results Build and enhance developer tooling, CI/CD pipelines, and automation (including AI-assisted workflows) Collaborate closely with platform teams to ensure smooth handover and long-term ownership Share best practices and mentor teams What You Bring 8+ years of backend engineering experience, strong in Java and microservices Proven experience modernising production systems at scale Solid API design and distributed systems knowledge Hands-on mindset: you write code, not just diagrams Experience using modern AI developer tools (e.g. Copilot, LLM-based refactoring/testing tools) Pragmatic, delivery-focused approach with strong collaboration skills If you enjoy building products end-to-end—from models to production—we’d love to hear from you.