Senior Backend Developer – Developer Platform

🏢 Summary: Senior React Developer role focused on building and optimizing modern, scalable web applications using cutting-edge front-end technologies in a hybrid work model. The position involves collaborating with cross-functional teams, implementing micro front-end architectures, and ensuring high-quality code through modern testing practices. It offers the opportunity to drive innovation and continuously enhance technical expertise. 🗂️ Requirements: 5+ years of experience in front-end web development, Strong expertise in React, Strong expertise in TypeScript, Experience with testing frameworks (Jest, Cypress, or Playwright), Experience building responsive, scalable web applications, Familiarity with micro front-end architecture, Knowledge of reactive programming (RxJS), Experience with modern build tools, Experience working in Agile SDLC environments, Legal right to work in the European Union 📃 Skills: React, Angular, TypeScript, JavaScript, Jest, Cypress, Playwright, RxJS, Webpack, Vite, Vitest, SSR, CSS-in-JS, HTML, CSS 🏢 Description: Unleash the Future of Web Applications — Drive Innovation with Cutting-Edge Front-End Technologies! Warsaw-based opportunity with hybrid work model As a Senior Front-End Developer , you will be working for our client, a leader in web application innovation within the technology industry. You’ll contribute to building and executing challenging projects across a variety of initiatives, collaborating closely with stakeholders, UX designers, and development teams to transform requirements into high-impact deliverables. This role offers a unique chance to learn new technologies and continually elevate your skills while shaping the future of digital experiences. Your main responsibilities: Develop and maintain modern, dynamic web applications using React, Angular, and TypeScript. Collaborate with cross-functional teams to translate user requirements into clean, scalable code. Implement best practices in testing using Jest, Cypress, or Playwright to ensure quality and performance. Integrate micro front-end architectures and reactive programming techniques such as RxJS. Optimize applications for maximum speed, scalability, and responsiveness. Contribute to code reviews, documentation, and continuous improvement processes. Leverage modern build tools like Webpack and Vite to streamline development workflows. Stay updated on industry trends and introduce innovative solutions to technical challenges. You're ideal for this role if you have: 5+ years of hands-on experience in front-end web development. Strong expertise in React, Angular, TypeScript, and testing frameworks like Jest, Cypress, or Playwright. Proven ability to deliver rich, responsive web applications with clean code. Familiarity with micro front-end architectures and reactive programming, particularly RxJS. Experience working in agile SDLC environments, including research, design, and engineering phases. Excellent communication skills and ability to manage multiple projects simultaneously. Self-motivated, innovative mindset with strong organizational skills. It is a strong plus if you have: (optional) Bachelor's degree in Computer Science or related field. Experience with SSR, CSS-in-JS, Vite, Vitest, and Webpack. Knowledge of micro front-end development and advanced build pipelines. Language Required for the role: Fluent Polish and English Eligibility for the role: Only candidates with an existing legal right to work in the European Union will be considered for this role. #MAKEYourCareerBETTER Interested? Apply now and include your CV (preferably in English) along with a statement confirming your consent to the processing and storage of your personal data.

🏢 Summary: Senior Java Developer role focused on building and optimizing scalable backend systems for real-time data processing in a fully remote environment. The position involves developing Java 17+ and Spring Boot applications, managing Kafka streams, implementing CI/CD pipelines, and maintaining high-quality testing and database solutions. 🗂️ Requirements: 5+ years of Java development experience, Java 17+ proficiency, Spring Boot expertise, REST API design experience, Apache Kafka experience, JUnit knowledge, Mockito knowledge, CI/CD experience, Jenkins familiarity or GitLab CI familiarity, Good Polish language skills, Communicative English level, Legal right to work in the European Union 📃 Skills: Java, Spring, Kafka, JUnit, Mockito, REST, Jenkins, GitLab, PostgreSQL, RabbitMQ, OpenShift, Prometheus, Grafana, JMeter 🏢 Description: Unleash innovative backend solutions — shape the future of real-time data processing! 100% remote work. As a Senior Java Developer, you will be working for a client focused on building robust, scalable software solutions. You will contribute to advancing data-driven platforms, delivering impactful backend components that support critical business operations and digital transformation. Your main responsibilities: - Develop and optimize Java 17+ applications with Spring Boot, focusing on REST API creation and integration. - Design and write automated tests, including unit, integration, contract, and API testing using JUnit, Mockito, and REST Assured. - Manage Apache Kafka streams, ensuring seamless real-time data processing and system reliability. - Implement CI/CD pipelines with Jenkins or GitLab CI to improve development workflows. - Maintain and enhance PostgreSQL database solutions, ensuring data integrity and performance. - Collaborate across teams to troubleshoot and resolve complex technical issues. - Document technical specifications and participate in code reviews. You’re ideal for this role if you have: - At least 5 years of professional experience in Java development. - Advanced knowledge of Java 17+, Spring Boot, and REST API design. - Proven expertise with Apache Kafka. - Experience with testing frameworks such as JUnit and Mockito. - Familiarity with CI/CD tools like Jenkins or GitLab CI. Nice to have: - Working knowledge of PostgreSQL and RabbitMQ. - Experience with OpenShift, Prometheus, Grafana, or JMeter. Language requirements: - Polish: Good command. - English: Communicative level. Eligibility: - Only candidates with an existing legal right to work in the European Union will be considered. Interested candidates should apply with a CV, preferably in English, including consent to the processing and storage of personal data.

🏢 Summary: Senior Backend Developer role focused on building and maintaining internal banking architecture tooling using Java and Node.js in a hybrid Krakow-based environment. The position involves developing backend services, APIs, web UI components, and AI-agent orchestration solutions to support enterprise-scale digital transformation. Candidates should have strong software engineering experience, database expertise, and knowledge of modern integration and automation practices. 🗂️ Requirements: 5+ years of software engineering experience, Strong expertise in Node.js, Strong expertise in Java, Experience with relational databases, Proficiency in PostgreSQL, Experience with JavaScript/TypeScript frameworks, Knowledge of agentic application engineering, Experience with MCP integration patterns, API design experience, Experience with tool/function calling, Production engineering mindset, Solution design skills, Fluent English, Legal right to work in the European Union 📃 Skills: Java, Node.js, PostgreSQL, JavaScript, TypeScript, MCP, API, SQL, AI, DevOps 🏢 Description: Empower innovative architecture tools — shape the future of banking technology! Krakow-based opportunity with hybrid work model (up to 3 remote days per week). As a Senior Backend Developer – Java and Node.js Platforms , you will be working for our client, a leading international bank. You’ll contribute to designing, building, and maintaining cutting-edge internal tooling that supports the bank’s Future State Architecture across CTO Platforms. Your work will enable seamless integration of data, workflows, and autonomous AI agents, helping redefine technology governance at scale and driving digital transformation. Your main responsibilities: Design, develop, and maintain reliable internal tooling supporting Future State Architecture (FSA) with a focus on security, resilience, and usability. Build backend services and APIs using Node.js and/or Java, integrating with PostgreSQL and other enterprise data sources. Develop web UI components utilizing modern JavaScript/TypeScript frameworks to deliver intuitive user workflows. Apply agentic engineering practices to orchestrate autonomous AI agents for building, testing, and deploying software. Implement secure, efficient integration patterns (e.g., MCP, API design, tool/function calling) across the architecture ecosystem. Collaborate with architects, platform engineers, and stakeholders to translate architectural needs into effective technical solutions. Ensure solutions adhere to client's engineering standards, including testing, performance, security, and operational readiness. Support continuous improvement initiatives through automation, code reviews, and operational support for live systems. You're ideal for this role if you have: At least 5 years of experience in software engineering, with strong expertise in Node.js and/or Java . Proficiency with relational databases , particularly PostgreSQL (data modeling, query optimization). Web UI development experience with modern JavaScript/TypeScript frameworks . Knowledge of agentic application engineering , including orchestration of autonomous AI agents. Experience with integration patterns such as MCP , API design , and tool/function calling . A production engineering mindset, emphasizing security, resilience, performance, and observability . Solution design skills for internal platforms and tooling. Excellent English communication skills and proven experience in stakeholder collaboration within a global environment. It is a strong plus if you have: Certifications or experience in automation, DevOps, or related fields. Additional familiarity with cloud services or enterprise architecture frameworks. Language Required for the role: Fluent English (spoken and written). Eligibility to work in: Only candidates with an existing legal right to work in the European Union will be considered for this role. #MAKEYourCareerBETTER Interested? Apply now and include your CV (preferably in English) along with a statement confirming your consent to the processing and storage of your personal data.

🏢 Summary: Senior Backend Developer role focused on designing, developing and scaling a modern web platform using Python and Django. The position involves architectural decisions, performance optimization, async processing and integrations with external systems. Strong ownership of code quality and technical direction is expected. 🗂️ Requirements: Minimum 5 years of backend development experience, Strong knowledge of Python, Commercial experience with Django, Experience with Django REST Framework, Practical experience with PostgreSQL, Experience with Docker and Docker Compose, Knowledge of asynchronous processing (Celery, Redis, queues), Ability to design and document REST APIs, Experience with system architecture and scalability, Experience with external API integrations 📃 Skills: Python, Django, DRF, PostgreSQL, Docker, Redis, Celery, REST, API, Angular, CQRS, DDD 🏢 Description: Szukamy doświadczonego Senior Backend Developera , który pomoże nam rozwijać i skalować nowoczesną platformę webową. Jeśli Backend to Twoje naturalne środowisko, a architektura, jakość kodu i odpowiedzialność techniczna są dla Ciebie ważniejsze niż „feature factory” – zapraszamy. Zakres obowiązków: Projektowanie i rozwój Backendu w Pythonie ( Django / Django REST Framework ) Współtworzenie architektury systemu (monolit + integracje, async, background tasks) Optymalizacja wydajności i skalowalności aplikacji Integracje z systemami zewnętrznymi (API, webhooki, płatności, usługi third-party) Dbanie o jakość kodu: code review, testy, dobre praktyki Współpraca z frontendem (Angular) i zespołem produktowym Realny wpływ na decyzje technologiczne Wymagania: Minimum 5 lat doświadczenia w Backendzie Bardzo dobra znajomość Pythona i Django Doświadczenie z Django REST Framework Praktyczna znajomość baz danych PostgreSQL Doświadczenie z Docker / Docker Compose Znajomość zagadnień async (Celery, Redis, kolejki) Umiejętność projektowania API i pracy z dokumentacją Samodzielność, odpowiedzialność i techniczne myślenie Mile widziane: Doświadczenie w projektowaniu większych systemów (DDD, CQRS, wzorce projektowe) Praca z systemami legacy i ich stopniową refaktoryzacją Doświadczenie w edukacji online / platformach SaaS Znajomość Angulara (na poziomie współpracy z FE) Oferujemy: Realny wpływ na produkt i architekturę Pracę przy sensownym, długoterminowym projekcie Dużą autonomię techniczną Elastyczne godziny pracy i pracę zdalną Współpracę B2B lub UoP Wynagrodzenie adekwatne do doświadczenia Jeśli lubisz backend, który ma znaczenie , a nie tylko „kolejne endpointy” - odezwij się. Etapy rekrutacji: 1. Zaproszenie na video screening 2. Zadanie rekrutacyjne sprawdzające znajomość DRF 3. Rozmowa miękko-techniczna -> po ok. 5 dniach od odesłania zadania, po pozytywnej jego ocenie umawiamy spotkanie online (ok. 40-min.) + krótki test kompetencji logicznych (online 40 minut)

🏢 Summary: Senior Backend Java Developer role focused on designing and building scalable, high-performance backend systems using Java and Spring Boot in a cloud-native environment. The position involves developing enterprise-grade solutions, ensuring performance and security, and supporting containerized deployments. The role requires strong experience with modern backend technologies and infrastructure tools. 🗂️ Requirements: 8+ years of backend development experience, Strong experience with Java 17+, Strong experience with Spring and Spring Boot, Experience with Spring Security, Experience with SQL databases, Experience with Maven, Experience with Git and CI/CD pipelines, Experience with testing frameworks (JUnit, AssertJ, Hamcrest), Experience with Kubernetes and Helm, Experience with Bash or Shell scripting, Experience with cloud-native applications, Experience in enterprise environments 📃 Skills: Java, Spring, SpringBoot, SpringSecurity, SQL, Maven, Git, CICD, JUnit, AssertJ, Hamcrest, Kubernetes, Helm, Bash, Shell, Docker, PostgreSQL 🏢 Description: Senior Backend Java Developer Location: Warsaw, Poland (hybrid – 2 days/week in the office) About the Role We’re looking for a Senior Backend Java Developer to design and build scalable, high-performance backend systems for international products. You’ll work in a collaborative environment, contribute to architectural decisions, and mentor other engineers. Responsibilities Design, develop, and maintain backend systems using Java 17+ and Spring Boot Ensure scalability, performance, and security of solutions Work with SQL databases (e.g. PostgreSQL) Support deployments using Docker, Kubernetes, and Helm Use Bash/Shell for automation and integration tasks Lead technical discussions and mentor team members Collaborate in Agile (Scrum) teams and communicate in English Requirements Strong experience with Java 17+, Spring / Spring Boot / Spring Security Experience with cloud-native applications Maven, SQL, Git (GitHub, CI/CD) Testing frameworks (JUnit, AssertJ, Hamcrest) Kubernetes, Helm Bash/Shell scripting English B2/C1 Experience in enterprise environments 8+ years of backend development experience Nice to Have PostgreSQL, Hibernate/JPA Kafka, event-driven architecture Microservices architecture Python Knowledge of C or Go CI/CD tools, JIRA Monitoring tools (Grafana, Prometheus, Kibana) Security best practices (OWASP) Qualifications Degree in Computer Science or related field

🏢 Summary: Senior React Front-End Developer role focused on building and maintaining scalable platform-wide React libraries and design system components for a major financial institution. The position involves developing reusable front-end solutions, ensuring quality through testing, and supporting product teams with platform integration. It emphasizes performance, accessibility, and high engineering standards within a hybrid work model. 🗂️ Requirements: 5+ years of experience in front-end development with React, Strong expertise in JavaScript and TypeScript, Experience building and maintaining scalable front-end applications and NPM packages, Experience with unit and end-to-end testing, Proficient use of Git including advanced branch and commit management, Knowledge of accessibility standards and WCAG, Experience with Jira, Confluence, and Bitbucket, Good command of Polish and communicative English, Legal right to work in the European Union 📃 Skills: React, JavaScript, TypeScript, NPM, CSS, Jest, Testing, Cypress, Git, WCAG, Jira, Confluence, Bitbucket, ReactNative, Capacitor, WebView 🏢 Description: Empower innovation at scale — shape the future of front-end technology! Warszawa-based opportunity with hybrid work model As a Senior React Front-End Developer – Platform Integration and Design Systems , you will be working for our client, a leading financial institution, delivering robust and scalable front-end solutions. Join a team committed to building advanced platform components that empower seamless user experiences and drive digital transformation. Your main responsibilities: Develop and maintain platform-wide React libraries and components aligned with the Bank’s Design System. Implement and optimize generic functionalities and innovative technical solutions for front-end teams. Write and sustain comprehensive unit and end-to-end tests to ensure high-quality deliverables. Ensure consistency, performance, and accessibility standards are upheld across all solutions. Collaborate with cross-functional platform teams and UI/UX designers to refine components and share best practices. Provide technical guidance and support to product teams utilizing the platform solutions. Maintain clear and detailed documentation for developed components and functionalities. You're ideal for this role if you have: Over 5 years of professional experience in front-end development with React. Strong expertise in JavaScript, TypeScript, NPM, and CSS. Proven experience in building and maintaining scalable front-end applications and NPM packages. Strong knowledge of unit and end-to-end testing (e.g., Jest, Testing Library, Cypress). Proficient use of the Git version control system, including managing branches and commits (rebase, cherry-pick, revert, squash, changing commit order and descriptions). Good understanding of accessibility principles (a11y), WCAG standards, and building accessible interfaces. Experience working with Jira, Confluence, and Bitbucket. It is a strong plus if you have: Experience working with design systems or contributing to their development. Knowledge of microfrontend architecture and integration challenges. Experience with hybrid mobile applications such as React Native, Capacitor, or WebView. Familiarity with AI tools or agents in software development projects. Language required for the role: Good command of Polish and Communicative English. Eligibility for the role: Only candidates with an existing legal right to work in the European Union will be considered for this role. #MAKEYourCareerBETTER Interested? Apply now and include your CV (preferably in English) along with a statement confirming your consent to the processing and storage of your personal data.

🏢 Summary: Senior Backend Developer role focused on designing and implementing core components of a high-performance trading platform in a cloud-native, microservices environment. The position involves building low-latency order management and event-driven distributed systems using Java/Kotlin on AWS. You will work within a Scrum team to deliver secure, scalable backend services for financial infrastructure. 🗂️ Requirements: Bachelor’s degree in Computer Science, IT or equivalent experience, 6+ years of experience in Java or Kotlin, Experience with Docker and Kubernetes, Strong knowledge of AWS cloud platform, Experience with CI/CD pipelines and automation, Knowledge of microservices architecture, Experience working with distributed systems, Competence in messaging systems, Experience with distributed caching, Understanding of monitoring and observability tools, English proficiency minimum B2 📃 Skills: Java, Kotlin, Kubernetes, Docker, Jenkins, GitLab, AWS, Microservices, CI/CD, Messaging, Caching, Scrum 🏢 Description: Employer: Swiss IT Company in Banking Infrastructure Rate: 6000 - 7500 Eur net per month Cooperation model: B2B Start date: ASAP Recruitment process:  3 steps (pre - screening, technical interview, technical task) Technology stack: Java or Kotlin, Kubernetes, Docker, Jenkins, Gitlab, AI Tools, AWS Team: 20-person Scrum team responsible for separate microservices We are currently looking for a Senior Backend Developer based in Poland (preferred locations: Wrocław, Poznań or fully remote). In this role, you will contribute to the design and implementation of strategic backend components within a high-performance financial technology platform. You will work on infrastructure responsible for order management, execution logic, smart routing mechanisms, and event-driven business services in a cloud-native environment. This is an opportunity to join a fast-growing, product-driven fintech organisation operating in a technically demanding domain with strong market demand and long-term growth potential. Your role is: -> Designing and implementing new releases of a core trading platform -> Contributing to architecture decisions around: low-latency order management execution algorithm smart order routing event driven and distributed systems -> Engineering and operating distributed services in cloud environments -> Collaborating closely with Product, Engineering Leadership, and cross-functional teams -> Ensuring solutions follow current industry best practices and architectural standards -> Designing with security, authentication and authorization in mind Your skills and experiences: -> Bachelor’s degree in Computer Science, IT or equivalent practical experience -> Experience with container orchestration (Docker and Kubernetes) -> 6+ years of experience in Java and/or Kotlin -> Solid understanding of monitoring, observability and diagnostics tooling -> Strong knowledge of cloud platform AWS -> Experience with CI/CD pipelines and automation -> Knowledge of microservices architecture and the ability to work within a distributed system environment -> Proven competence in messaging systems and distributed caching -> Strong spoken and written English (min B2) Nice to have: + Experience with reactive programming patterns + Strong clean-code mindset and experience with test automation Our client offers: + Great opportunity for personal development in a stable and friendly large multinational company + Frequent company events + Flexible working hours If interested, please apply safely through this portal (application rules are in accordance with GDPR). Employment agency Nr 17138.

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

🏢 Summary: Senior Java Developer role focused on designing and building high-performance, scalable backend systems in a distributed microservices environment for the financial sector. The position involves developing REST APIs, processing large data volumes, and contributing to architecture and CI/CD in cloud-based environments. The role requires strong expertise in Java, Spring, distributed systems, and Kubernetes. 🗂️ Requirements: Minimum 10 years of software development experience, Very good knowledge of Java and Spring, Strong understanding of REST APIs, HTTPS, microservices, and message queues, Ability to design high-availability, scalable, high-performance systems, Very good knowledge of relational databases and SQL, Knowledge of distributed systems and data processing, Hands-on experience with Kubernetes and cloud platforms (GCP preferred), Familiarity with CI/CD pipelines, Experience working in Agile methodologies, Fluent Polish and English, Residence in Poland 📃 Skills: Java, Spring, REST, HTTPS, Microservices, MQ, SQL, Kubernetes, GCP, CI/CD, Agile, DistributedSystems, DataProcessing 🏢 Description: We are looking for an experienced Senior Java Developer to join a team responsible for building and developing modern backend systems in a distributed environment. The projects involve high-performance and scalable solutions used in the financial sector, with a focus on processing large volumes of data and microservices architecture. Your tasks Designing and developing backend systems based on Java Creating and evolving a microservices architecture Building and maintaining REST APIs and system integrations Designing solutions that meet high availability and performance requirements Working with systems that process large volumes of data Collaborating with the team using Agile methodologies Participating in architecture design and technical decision-making Implementing and optimizing CI/CD processes and ensuring system security Requirements Minimum 10 years in software development Very good knowledge of Java (backend) and Spring Strong understanding of REST APIs, HTTPS, microservices, and message queues (MQ) Ability to design high-availability, scalable, and high-performance systems Very good knowledge of relational databases (SQL) Familiarity with CI/CD pipelines and Agile ways of working Knowledge of distributed systems and data processing Hands-on work with Kubernetes and cloud platforms (GCP preferred) Fluent Polish and English required Residing in Poland required Nice-to-have requirements Knowledge of Go, Rust, or similar system-level languages Experience with NoSQL and analytical databases, e.g., ClickHouse Frontend development experience Familiarity with the banking sector (trade lifecycle, FX, post-trade processing) Banking experience / FX experience (forex) Working from the office in Krakow 6 times per month What we offer Great Place to Work since 2015 - it’s thanks to feedback from our workers that we get this special title and constantly implement new ideas Employment stability - revenue of PLN 2.1BN, no debts, since 2006 on the market We share the profit with Workers - over PLN 76M has already been allocated for this aim since 2022 Attractive benefits package - private healthcare, benefits cafeteria platform, car discounts and more Comfortable workplace – class A offices or remote work Dozens of fascinating projects for prestigious brands from all over the world PLN 1 000 000 per year for your ideas - with this amount, we support the passions and voluntary actions of our workers Investment in your growth – meetups, webinars, training platform and technology blog – you choose Fantastic atmosphere created by all Sii Power People If you want to work on systems with high operational significance — apply now!

🏢 Summary: Senior Backend Engineer role focused on building and scaling JVM-based services for large-scale payment processing systems in a cloud-native, microservices architecture. The position involves integrating external payment providers, implementing event-driven workflows, and ensuring high performance and reliability of distributed services. This is a long-term remote project enhancing payment flows and compliant financial features. 🗂️ Requirements: 5+ years commercial backend development in JVM ecosystem, Experience integrating external payment platforms or financial APIs, GoCardless integration experience, Experience with cloud-based relational databases, Experience with container orchestration tools, Experience with messaging systems and asynchronous communication, Knowledge of direct debit or instant bank transfer mechanisms, Fluent English (spoken and written), Residence in Poland 📃 Skills: Java, JVM, GoCardless, SQL, Kubernetes, Docker, Messaging, Microservices, Cloud, APIs, Payments 🏢 Description: We are looking for a Senior Backend Engineer experienced in JVM technologies to join a remote product development team working on large‑scale payment processing solutions. The role involves contributing to a long‑term initiative aimed at enhancing payment flows and supporting key business requirements through modern, service‑oriented architecture. Your tasks Designing and developing backend services using JVM technologies in a cloud‑native environment Creating and maintaining integrations between internal systems and external payment providers Implementing event‑driven communication patterns and message‑based workflows Ensuring the scalability, performance, and reliability of distributed microservices Collaborating closely with product and architecture teams to deliver compliant payment features Participating in code reviews and contributing to the continuous improvement of engineering practices Requirements Minimum 5 years of commercial experience in backend development within the JVM ecosystem Hands‑on background in integrating external payment platforms or similar financial APIs GoCardless integration experience Familiarity with cloud‑based relational databases and container orchestration tools Experience with messaging systems and asynchronous communication patterns Knowledge of direct debit flows or instant bank transfer mechanisms will be a strong advantage Strong command of English, both spoken and written Residing in Poland required