Freelance Kotlin Developer (Fulltime)

🏢 Summary: The offer is for a Backend Developer role focused on building and maintaining high-performance, low-latency systems for advertising and e-commerce platforms. The position involves developing scalable microservices and APIs using Kotlin and Spring Boot, working with real-time event processing, and contributing to system architecture and scalability. The role also includes production support and collaboration within cross-functional engineering teams. 🗂️ Requirements: 3+ years of professional experience in Java backend development, Very good knowledge of Kotlin, Very good knowledge of Spring Boot, Hands-on experience with microservices architecture, Practical experience with NoSQL databases, Experience with MongoDB, Experience building and maintaining backend systems and APIs, Understanding of system design and scalable architecture principles, Experience with high-performance and high-scale systems, English level B2, Polish level C1, Experience with AI-powered coding assistants, Work permit for EU and ability to work from EU region, Availability for occasional visits to Warsaw office 📃 Skills: Java, Kotlin, Spring, SpringBoot, Microservices, MongoDB, NoSQL, REST, API, AI, Claude, Copilot, Cursor 🏢 Description: 🟣 You will be: developing and maintaining backend systems for advertising and e-commerce platforms, building low-latency, high-performance services processing large volumes of data, developing scalable microservices and APIs using Kotlin and Spring Boot, working on real-time event processing and advertising targeting mechanisms, contributing to architecture design and system scalability improvements, collaborating with stakeholders and supporting engineering best practices, including code reviews and code quality standards, participating in technical readiness/on-call support for production incidents a few days per month. 🟣 Your profile: 3+ years of professional experience in Java backend development, very good knowledge of Kotlin and Spring Boot, openness to occasional visits to the Warsaw office (1–2 days per quarter), hands-on experience with microservices architecture, practical experience working with NoSQL databases, especially MongoDB, experience building and maintaining backend systems and APIs, understanding of system design and scalable architecture principles, experience working with high-performance and high-scale systems, strong analytical thinking and problem-solving skills, ability to collaborate effectively with stakeholders and engineering teams, good communication skills in English (B2) and Polish (C1), practical experience using AI-powered assistants (e.g. Claude Code, GitHub Copilot, Cursor) to improve productivity, quality, or decision-making in software delivery. immediate availability or a short notice period is preferred. Work from the European Union region and a work permit are required. 🟣 Nice to have: experience applying GenAI in a more structured way within the SDLC, including defined workflows, prompt patterns, or tool integrations embedded into daily work, interest in and familiarity with emerging AI-driven practices (e.g. agent-based workflows, automation patterns, AI-augmented development), with a willingness to explore and experiment beyond standard approaches. 🟣 Recruitment Process: CV review – HR call – Technical Interview – Client Interview – Decision 🎁 Benefits 🎁 ✍ Development: development budgets of up to 6,800 PLN, we fund certifications e.g.: AWS, Azure, access to Udemy, O'Reilly (formerly Safari Books Online) and more, events and technology conferences, technology Guilds, internal training, Xebia Upskill. 🩺 We take care of your health: private medical healthcare, multiSport card - we subsidise a MultiSport card, mental Health Support. 🤸‍♂️ We are flexible: B2B or employment contract, contract for an indefinite period.

🏢 Summary: Senior/Staff Backend Engineer role focused on building and evolving a large-scale, event-driven platform using Java, Kafka Streams, and AWS. The position involves hands-on work with high-volume data flows, real-time stream processing, distributed systems, and production reliability. You will take strong technical ownership in a small team, shaping architecture, standards, and production readiness. 🗂️ Requirements: 7+ years of backend engineering experience, Strong hands-on experience with Java, Strong hands-on experience with Spring Boot, Deep production experience with Kafka Streams (topologies, joins, aggregations, windowing, state stores), Experience with event-driven or distributed systems, Hands-on experience with AWS services, Experience with Kubernetes and containerized deployments, Experience with PostgreSQL, MongoDB, and Redis, Strong knowledge of monitoring, debugging, and performance optimization, Ability to work independently in evolving technical environments, Professional English communication skills 📃 Skills: Java, Spring, Kafka, KafkaStreams, AWS, EKS, S3, SQS, SNS, Kinesis, Lambda, Kubernetes, PostgreSQL, MongoDB, Redis, Terraform, Helm, Prometheus, Grafana, Micrometer, Kotlin 🏢 Description: Senior / Staff Backend Engineer (Java, Kafka Streams, AWS) Location: Kraków, hybrid Contract: B2B or UoP B2B budget: up to 210 PLN/h + VAT Work model: around 3 days per week from the office We are looking for a Senior or Staff Backend Engineer to join a small, high-impact engineering team building a large-scale, event-driven platform. This is a hands-on role for someone who enjoys working close to real production systems: high-volume data flows, asynchronous processing, external integrations, reliability, observability and technical ownership. You will join a team where the codebase and domain are evolving, so this is a good opportunity for an engineer who does not need every problem to be fully defined before getting started. You will be expected to investigate, create structure, improve standards and make pragmatic technical decisions. What you will do Build and evolve backend services using Java and Spring Boot Design and maintain real-time event-processing flows using Kafka Streams Work with stream-processing concepts such as topologies, transformations, joins, aggregations, stateful processing and data routing Integrate external systems and infrastructure into a scalable internal platform Improve reliability, observability and production readiness of services handling high-volume data Investigate production issues, performance bottlenecks and data-flow problems Work with AWS, Kubernetes, PostgreSQL, MongoDB, Redis, Terraform and Helm Contribute to code reviews, architecture decisions, documentation and engineering standards Collaborate with product, platform and engineering stakeholders across an international environment What we are looking for 7+ years of backend engineering experience Strong, current hands-on experience with Java and Spring Boot Deep practical experience with Kafka Streams in production This should go beyond Kafka producers/consumers and include work with stream-processing logic, joins, aggregations, windowing, state stores or topology design Background in event-driven, distributed or real-time systems Hands-on AWS experience, ideally with services such as EKS, S3, SQS, SNS, Kinesis or Lambda Experience with Kubernetes , containers and production deployment environments Good understanding of databases such as PostgreSQL, MongoDB and Redis Strong production mindset: monitoring, debugging, reliability, performance and incident investigation Ability to work independently in an evolving and not always fully documented technical environment Clear English communication skills and confidence explaining technical topics to both engineers and non-technical stakeholders Nice to have Kotlin experience Experience with high-throughput data processing or streaming platforms Terraform, Helm, Prometheus, Grafana, Micrometer or similar observability tooling Experience in a small product team, scale-up or ownership-heavy engineering environment Familiarity with AI-assisted development tools What you can expect A technically challenging role focused on real production systems rather than isolated feature delivery Strong ownership Small team setup with room to influence architecture, standards and ways of working International engineering environment Clear recruitment process focused on practical engineering discussions Recruitment process Introductory conversation with the Hiring Manager Technical interview focused on Kafka/use cases and Java/code quality Final discussion with senior technical leadership The full company and product context will be shared during the first recruiter call.

🏢 Summary: The role involves developing and maintaining high-performance backend systems for advertising and e-commerce platforms, focusing on scalable microservices and real-time data processing using Kotlin and Spring Boot. You will design low-latency services, contribute to system architecture, and support production environments in a high-scale setting. The position also emphasizes AI-assisted development practices and collaboration within engineering teams. 🗂️ Requirements: 3+ years of backend development experience, Very good knowledge of Kotlin, Very good knowledge of Spring Boot, Hands-on experience with microservices architecture, Experience with NoSQL databases, Experience with MongoDB, Experience building and maintaining backend systems and APIs, Understanding of system design and scalable architecture, Experience with high-performance and high-scale systems, English B2 level, Polish C1 level, Work permit in the European Union, Openness to occasional visits to Warsaw office, Experience using AI-powered coding assistants 📃 Skills: Kotlin, SpringBoot, MongoDB, NoSQL, Microservices, REST, APIs, GenAI, Claude, GitHubCopilot, Cursor, AWS, Azure 🏢 Description: 🟣 You will be: developing and maintaining backend systems for advertising and e-commerce platforms, building low-latency, high-performance services processing large volumes of data, developing scalable microservices and APIs using Kotlin and Spring Boot, working on real-time event processing and advertising targeting mechanisms, contributing to architecture design and system scalability improvements, collaborating with stakeholders and supporting engineering best practices, including code reviews and code quality standards, participating in technical readiness/on-call support for production incidents a few days per month. 🟣 Your profile: 3+ years of professional experience in backend development, very good knowledge of Kotlin and Spring Boot, openness to occasional visits to the Warsaw office (1–2 days per quarter), hands-on experience with microservices architecture, practical experience working with NoSQL databases, especially MongoDB, experience building and maintaining backend systems and APIs, understanding of system design and scalable architecture principles, experience working with high-performance and high-scale systems, strong analytical thinking and problem-solving skills, ability to collaborate effectively with stakeholders and engineering teams, good communication skills in English (B2) and Polish (C1), practical experience using AI-powered assistants (e.g. Claude Code, GitHub Copilot, Cursor) to improve productivity, quality, or decision-making in software delivery. Work from the European Union region and a work permit are required. 🟣 Nice to have: experience applying GenAI in a more structured way within the SDLC, including defined workflows, prompt patterns, or tool integrations embedded into daily work, interest in and familiarity with emerging AI-driven practices (e.g. agent-based workflows, automation patterns, AI-augmented development), with a willingness to explore and experiment beyond standard approaches. 🟣 Recruitment Process: CV review – HR call – Technical Interview – Client Interview – Decision 🎁 Benefits 🎁 ✍ Development: development budgets of up to 6,800 PLN, we fund certifications e.g.: AWS, Azure, access to Udemy, O'Reilly (formerly Safari Books Online) and more, events and technology conferences, technology Guilds, internal training, Xebia Upskill. 🩺 We take care of your health: private medical healthcare, multiSport card - we subsidise a MultiSport card, mental Health Support. 🤸‍♂️ We are flexible: B2B or employment contract, contract for an indefinite period.

🏢 Summary: The offer is for a Backend Engineer responsible for building and maintaining high-performance backend systems in a cloud-based environment using Java, Kubernetes, and AWS. The role focuses on developing containerized applications and operating them reliably in the AWS cloud. It is a long-term remote B2B contract centered on scalable and cloud-native technologies. 🗂️ Requirements: Proficiency in Java, Experience with JVM ecosystem and Spring Boot, Experience with Kubernetes and Docker, Hands-on experience with AWS services (Lambda, EC2, ECS, EKS), Basic knowledge of Terraform, Minimum 1-2 years of AWS or other cloud platform experience, Understanding of containerization concepts, Knowledge of Camunda or AWS Step Functions 📃 Skills: Java, Python, Spring, SpringBoot, Kubernetes, Docker, AWS, Lambda, EC2, ECS, EKS, Terraform, Angular, Camunda, StepFunctions, JVM 🏢 Description: Backend Engineer (Java/Kubernetes/AWS): Introduction & Summary: This role requires a skilled Backend Engineer proficient in Java with experience in Kubernetes and AWS. The ideal candidate will be responsible for developing and maintaining efficient backend systems that prioritize performance and reliability while leveraging cloud technologies. What we offer: Full Remote Rate: 180-200 PLN/ H+ VAT Long Term B2B contract Main Responsibilities: Develop and maintain backend systems, running in Kubernetes in the AWS cloud, with a focus on performance and reliability. Build and manage containerized applications using tools like Docker and Kubernetes. Utilize cloud services, particularly AWS, to deploy and operate applications efficiently. Key Requirements: Proficiency in Java is required, with additional experience in Python as a plus. Experience with the JVM ecosystem, especially Spring Boot. Familiarity with frontend technologies, particularly Angular. Solid understanding of containerization technologies, including Docker and Kubernetes. Hands-on experience with AWS cloud services like Lambda, EC2, ECS, and EKS. Basic Terraform knowledge is essential. Minimum of 1-2 years working with AWS or equivalent experience with other cloud platforms. Knowledge of business process modeling or workflow orchestration tools such as Camunda or AWS Step Functions. Nice to Have: Experience with CI/CD pipelines. Familiarity with microservices architecture. Understanding of Agile methodologies. Other Details: This position may offer remote work flexibility. The role is for a long-term assignment focusing on cloud-based technologies in a dynamic environment.

🏢 Summary: Java Developer role focused on designing and maintaining scalable microservices-based backend systems using Spring technologies. The position involves building high-performance RESTful services, improving existing systems, and collaborating closely with cross-functional teams in a hybrid work model. 🗂️ Requirements: Minimum 2 years of experience with Java, Hands-on experience with microservices architecture, Experience with Spring and Spring Boot, Knowledge of REST APIs and integration patterns, Ability to work onsite in Warsaw 2 days per week 📃 Skills: Java, Microservices, Spring, SpringBoot, REST, Kubernetes, AWS, Azure, GCP, Kafka, RabbitMQ 🏢 Description: We’re looking for a Java Developers with solid experience in microservices architecture to join our growing team in Łódź. If you enjoy building scalable backend systems and like collaborating face-to-face a couple of days a week, this role is for you. Responsibilities Design, develop, and maintain Java-based microservices Build scalable, high-performance backend solutions Collaborate with product owners, architects, and other developers Write clean, testable, and well-documented code Participate in code reviews and technical discussions Support and improve existing systems Requirements Experience with Java minimum 2 years + Hands-on experience with microservices architecture Experience with Spring / Spring Boot Knowledge of REST APIs and integration patterns Ability to work onsite in Warsaw 2 days per week Nice to Have Experience with Kubernetes Cloud experience (AWS, Azure, or GCP) Knowledge of messaging systems (Kafka, RabbitMQ) Experience working in Agile/Scrum teams What We Offer Hybrid work model (2 days onsite in Warsaw) Competitive salary and benefits Modern tech stack and real impact on products Friendly, collaborative team culture Opportunities for learning and professional growth

🏢 Summary: Long-term remote B2B contract for a Backend Engineer responsible for building and maintaining high-performance backend systems in Java, deployed on Kubernetes within AWS. The role focuses on developing containerized applications and leveraging cloud services to ensure scalability and reliability. Work involves JVM-based technologies and cloud-native architecture. 🗂️ Requirements: Proficiency in Java, Experience with Spring Boot and JVM ecosystem, Hands-on experience with AWS services (Lambda, EC2, ECS, EKS), Minimum 1–2 years of experience with AWS or other cloud platforms, Strong knowledge of Docker and Kubernetes, Experience building and managing containerized applications, Basic knowledge of Terraform, Knowledge of Camunda or AWS Step Functions 📃 Skills: Java, Spring, JVM, AWS, Lambda, EC2, ECS, EKS, Kubernetes, Docker, Terraform, Camunda, StepFunctions, Angular, Python 🏢 Description: Backend Engineer (Java/Kubernetes/AWS): Introduction & Summary: This role requires a skilled Backend Engineer proficient in Java with experience in Kubernetes and AWS. The ideal candidate will be responsible for developing and maintaining efficient backend systems that prioritize performance and reliability while leveraging cloud technologies. What we offer: Full Remote Rate: 180-200 PLN/ H+ VAT Long Term B2B contract Main Responsibilities: Develop and maintain backend systems, running in Kubernetes in the AWS cloud, with a focus on performance and reliability. Build and manage containerized applications using tools like Docker and Kubernetes. Utilize cloud services, particularly AWS, to deploy and operate applications efficiently. Key Requirements: Proficiency in Java is required, with additional experience in Python as a plus. Experience with the JVM ecosystem, especially Spring Boot. Familiarity with frontend technologies, particularly Angular. Solid understanding of containerization technologies, including Docker and Kubernetes. Hands-on experience with AWS cloud services like Lambda, EC2, ECS, and EKS. Basic Terraform knowledge is essential. Minimum of 1-2 years working with AWS or equivalent experience with other cloud platforms. Knowledge of business process modeling or workflow orchestration tools such as Camunda or AWS Step Functions. Nice to Have: Experience with CI/CD pipelines. Familiarity with microservices architecture. Understanding of Agile methodologies. German languages Other Details: This position may offer remote work flexibility. The role is for a long-term assignment focusing on cloud-based technologies in a dynamic environment.

🏢 Summary: Backend Developer role focused on designing, building, and maintaining scalable Java and Kotlin-based applications and microservices within an international team. The position involves developing high-quality backend systems, collaborating with cross-functional teams, and optimizing distributed systems performance. The role emphasizes clean code, modern frameworks, and agile delivery practices. 🗂️ Requirements: 5+ years of backend development experience with Java 8+ and Kotlin, Strong knowledge of Spring Framework and Spring Boot, Experience building RESTful APIs and microservices, Experience with SQL and NoSQL databases, Understanding of Agile/Scrum methodologies 📃 Skills: Java, Kotlin, Spring, SpringBoot, REST, Microservices, SQL, NoSQL, PostgreSQL, MongoDB, Agile, Scrum 🏢 Description: We are looking for skilled Java & Kotlin Developers to join our growing technology team in Poland. As part of an international development group, you’ll design, build, and maintain scalable backend systems using Java and modern frameworks. You’ll collaborate closely with cross-functional teams to deliver high-quality, reliable, and efficient software solutions. Key Responsibilities Design, develop, and maintain Java-based applications and microservices. Write clean, efficient, and testable code following best practices and coding standards. Collaborate with front-end developers , DevOps engineers , and QA teams to ensure seamless integration and delivery. Participate in code reviews , architecture discussions, and agile ceremonies. Contribute to technical documentation and continuous improvement of development processes. Troubleshoot and optimize performance across distributed systems. Requirements 5+ years of experience in backend development using Java 8+ Kotlin . Strong understanding of Spring Framework / Spring Boot . Experience with RESTful APIs , microservices , and SQL / NoSQL databases (e.g., PostgreSQL, MongoDB). Knowledge of Agile / Scrum methodologies. Good command of English (B2 or higher) – Polish language skills are a plus. Nice to Have Experience with cloud platforms (AWS, Azure, or GCP). Familiarity with message brokers (Kafka, RabbitMQ). Knowledge of unit testing and test automation frameworks (JUnit, Mockito). Interest in DevOps or system design concepts. How to Apply If you’re passionate about building high-quality Java applications and want to be part of a dynamic engineering team, send your CV

🏢 Summary: The role involves designing and developing scalable backend systems in a microservices architecture using Java or Kotlin and Spring. The engineer will influence technical decisions while building payment and subscription platforms with event-driven communication and cloud-based solutions. The position includes working with modern architectural patterns and ensuring high code quality through testing and reviews. 🗂️ Requirements: Strong experience with Java and/or Kotlin, Solid knowledge of Spring and Spring Boot, Hands-on experience with SQL and relational databases, Experience with PostgreSQL, Proven experience with microservices architecture, Experience with event-driven systems, Practical experience with JUnit, Mockito, Testcontainers, Experience with AWS or GCP, Understanding of DDD, CQRS, Hexagonal Architecture, Experience with payment or subscription systems 📃 Skills: Java, Kotlin, Spring, SpringBoot, SQL, PostgreSQL, Microservices, Kafka, JUnit, Mockito, Testcontainers, AWS, GCP, DDD, CQRS, HexagonalArchitecture 🏢 Description: Senior Backend Engineer (Java/Kotlin) We are looking for an experienced Backend Engineer to join a team building modern, scalable systems based on a microservices architecture. This role offers real influence over technical decisions, system architecture, and the quality of delivered solutions—particularly within payment and subscription platforms. Responsibilities Design, develop, and maintain backend systems using Java or Kotlin and the Spring Framework Build and evolve microservices following DDD , CQRS , and Hexagonal Architecture principles Implement event-driven communication , ideally using Apache Kafka Work with relational databases ( PostgreSQL or other SQL databases ) and optimize queries Write unit and integration tests using JUnit, Mockito, and Testcontainers Contribute to the design and development of cloud-based solutions ( AWS or GCP ) Participate in code reviews and drive high engineering standards Collaborate closely with product and engineering teams to deliver business-critical features Requirements Strong experience with Java and/or Kotlin Solid knowledge of Spring / Spring Boot Hands-on experience with SQL and relational databases (preferably PostgreSQL ) Proven background in microservices-based architectures Experience with event-driven systems (Kafka is a strong plus) Practical experience with backend testing (JUnit, Mockito, Testcontainers) Experience working with cloud platforms ( AWS or GCP ) Good understanding of Domain-Driven Design (DDD) , CQRS , and Hexagonal Architecture Must-have: experience with payment systems and/or subscription-based platforms Nice to Have Experience working with high-scale, high-availability systems Knowledge of security and transactional data handling Background in product-driven, Agile environments

🏢 Summary: Senior Java Spring Boot Backend Developer role focused on building and modernizing a cloud-native Messaging Delivery Platform in the financial sector. The position involves developing scalable microservices, APIs, and containerized applications deployed on AWS using Kubernetes. It combines hands-on backend engineering with DevOps practices in an Agile environment. 🗂️ Requirements: Minimum 6 years of Java development experience, Strong hands-on experience with Spring Boot, Experience with microservices architecture, Practical experience with Kubernetes, Experience with AWS cloud environment, Experience with CI/CD tools (Jenkins, GitHub, Maven, Groovy), Strong knowledge of API design (REST, Swagger, OpenAPI, JSON), Experience with OAuth2 and API Gateway solutions, Experience working in Agile (Scrum, TDD), Legal right to work in the European Union 📃 Skills: Java, Spring, SpringBoot, Microservices, Kubernetes, AWS, Jenkins, GitHub, Maven, Groovy, REST, Swagger, OpenAPI, JSON, OAuth2, Kong, CI/CD, TDD, Scrum 🏢 Description: Unleash innovation at scale — drive the future of cloud-native, microservices architectures! Krakow-based opportunity with hybrid work model (3 remote days per week). As a Senior Java Spring Boot Backend Developer , you will be working for our client in the financial industry, focusing on the Messaging Delivery Platform—centralizing and modernizing message delivery to bank customers across multiple channels. Join a cutting-edge project that shapes the future of client communication through advanced distributed systems and cloud technology. Your main responsibilities: Develop high-quality, scalable backend applications using Java and Spring Boot, ensuring adherence to technical requirements and standards. Collaborate within a multidisciplinary Agile team to design, build, and enhance distributed microservices architectures. Implement and monitor API solutions using Swagger, OpenAPI, REST, and JSON standards, ensuring best practices. Deploy and manage containerized applications on Kubernetes, leveraging AWS cloud infrastructure. Integrate authentication and authorization mechanisms such as OAuth 2 and API Gateway solutions. Write and execute unit tests, contribute to automation testing efforts, and uphold quality benchmarks. Participate in code reviews, challenge implementations to maintain highest quality standards, and promote innovation. Keep abreast of current technologies, tools, and industry best practices, continuously enhancing your expertise. Support and mentor team members to foster a culture of technical excellence and knowledge sharing. You're ideal for this role if you have: Minimum 6 years of experience in Java development within a senior or expert capacity. Strong hands-on expertise with Spring Boot framework and microservices architecture. Practical experience with Kubernetes and Cloud environments, particularly AWS. Proficiency with CI/CD tools such as Jenkins, GitHub, Maven, and Groovy scripting. Deep understanding of API design principles, including Swagger, OpenAPI 3.0, REST, and JSON. Familiarity with authentication protocols like OAuth 2 and API Gateway solutions such as Kong. Robust knowledge of Agile practices, especially TDD and Scrum methodologies. Ability to work fluently in English, with excellent communication skills. It is a strong plus if you have: Certifications or additional experience with AWS services. Knowledge of automation testing frameworks. Experience with messaging systems or middleware. 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 Spring Boot Backend Developer role focused on building and modernizing a cloud-native Messaging Delivery Platform in the financial sector. The position involves designing and developing scalable microservices, APIs, and distributed systems deployed on Kubernetes and AWS. You will contribute to high-quality backend solutions within an Agile environment using modern DevOps and cloud practices. 🗂️ Requirements: Minimum 6 years of commercial experience in Java development, Strong hands-on experience with Spring Boot, Practical experience in microservices architecture, Experience with Kubernetes and AWS cloud environments, Proficiency with CI/CD tools: Jenkins, GitHub, Maven, Groovy, Strong knowledge of API design: Swagger, OpenAPI, REST, JSON, Experience with OAuth2 and API Gateway solutions such as Kong, Experience with unit testing and TDD practices, Knowledge of Agile methodologies, especially Scrum, Fluent English, Legal right to work in the EU 📃 Skills: Java, Spring, SpringBoot, Microservices, Kubernetes, AWS, Jenkins, GitHub, Maven, Groovy, Swagger, OpenAPI, REST, JSON, OAuth2, Kong, Docker, CICD, TDD, Scrum 🏢 Description: Unleash innovation at scale — drive the future of cloud-native, microservices architectures! Krakow-based opportunity with hybrid work model (3 remote days per week). As a Senior Java Spring Boot Backend Developer , you will be working for our client in the financial industry, focusing on the Messaging Delivery Platform—centralizing and modernizing message delivery to bank customers across multiple channels. Join a cutting-edge project that shapes the future of client communication through advanced distributed systems and cloud technology. Your main responsibilities: Develop high-quality, scalable backend applications using Java and Spring Boot, ensuring adherence to technical requirements and standards. Collaborate within a multidisciplinary Agile team to design, build, and enhance distributed microservices architectures. Implement and monitor API solutions using Swagger, OpenAPI, REST, and JSON standards, ensuring best practices. Deploy and manage containerized applications on Kubernetes, leveraging AWS cloud infrastructure. Integrate authentication and authorization mechanisms such as OAuth 2 and API Gateway solutions. Write and execute unit tests, contribute to automation testing efforts, and uphold quality benchmarks. Participate in code reviews, challenge implementations to maintain highest quality standards, and promote innovation. Keep abreast of current technologies, tools, and industry best practices, continuously enhancing your expertise. Support and mentor team members to foster a culture of technical excellence and knowledge sharing. You're ideal for this role if you have: Minimum 6 years of experience in Java development within a senior or expert capacity. Strong hands-on expertise with Spring Boot framework and microservices architecture. Practical experience with Kubernetes and Cloud environments, particularly AWS. Proficiency with CI/CD tools such as Jenkins, GitHub, Maven, and Groovy scripting. Deep understanding of API design principles, including Swagger, OpenAPI 3.0, REST, and JSON. Familiarity with authentication protocols like OAuth 2 and API Gateway solutions such as Kong. Robust knowledge of Agile practices, especially TDD and Scrum methodologies. Ability to work fluently in English, with excellent communication skills. It is a strong plus if you have: Certifications or additional experience with AWS services. Knowledge of automation testing frameworks. Experience with messaging systems or middleware. 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.