Jobs Java

• Project Description:

  One of the world's largest providers of products and services to the energy industry has a need to develop and support enterprise information system in Oil & Gas domain.

  
  Product being developed is a cloud solution for interpretation of geological and geophysical data. Project is based on SCRUM methodology.

  
  Our project is stable, long-term and constantly adopts new technologies such as newest Java and Eclipse RCP versions, cloud and GPU computing, microservices architecture and other innovative frameworks.

  
  Work supposes close cooperation with Customer team located in Houston and following Agile principles.
  Our team is senior, supportive and friendly.

   

• Responsibilities:

  • Collaborate closely with geophysicists, data scientists, and software engineers to translate scientific domain requirements into robust on-prem or Cloud software
  solutions.
  • Design, develop, and maintain high-performance applications for geophysical and geological data analysis, interpretation and visualization (e.g., seismic, horizon,
  fault, velocity model, etc.)
  • Present architectural designs and technical proposals to the architecture review board.
  • Ability to break down development tasks and lay out clear implementation roadmaps.
  • Implement and optimize computation algorithms
  • Design and develop both thin and thick client applications that interact with cloud-based microservices.
  • Ensure high code quality through unit testing, code reviews, security hardening and continuous integration with other domain tools
  • Provide technical support and lead user troubleshooting sessions to resolve issues and ensure smooth operation of DSG application.
  • Mentor junior developers and actively contribute to architectural and implementation decisions.
  • Embrace Agile/Scrum methodologies, delivering and demonstrating working solutions at the end of each sprint
  • Stay current with emerging technologies and trends in geophysical computing and software development.

   

• Mandatory Skills Description:

  6+ years of hands-on Java development experience
  Strong Java Core knowledge
  Experience with desktop development frameworks: Swing, SWT, or Eclipse RCP
  Proven experience designing and building complex systems end-to-end, not just maintaining or extending existing ones
  Practical understanding of multithreaded programming: ability to implement concurrency in code directly, not only through third-party libraries
  Solid knowledge of design patterns and software architecture principles
  Ability to clearly articulate past projects, personal responsibilities, and concrete individual contributions
  Experience working in non-microservices, non-cloud-native development environments (desktop, embedded, or domain-specific platforms)
  Stable career trajectory, no fragmented job history with short tenures

A global marketplace for savings and investments, providing users with seamless access to high-yield savings accounts and investment options from over 400 partner banks worldwide. The platform removes geographic barriers while ensuring transparency, convenience, and competitive rates. For banks, it delivers cost-efficient deposit funding and innovative Banking-as-a-Service solutions. The team is responsible for the integration of transaction accounts, hosted via our servicing banks, into the Raisin platform. They ensure smooth funding across all products, correctly routing incoming and outgoing payments to their intended destinations. The team consists of 10 members working collaboratively in a cross-functional setup.

Responsibilities:

• Deliver core services and high-quality solutions for a large-scale online platform and its banking systems.
•  Integrate externally developed components into existing applications.
• Define standards, share best practices, and contribute to continuous learning within the team.
• Perform software engineering tasks with a strong focus on quality and support teammates in maintaining the same standards.
• Conduct thorough code reviews, covering best practices, business rules, performance, security, and impact on other features/projects, always providing constructive and respectful feedback.
• Collaborate within the team to negotiate and document software development standards and practices.
• Research and propose multiple technical solutions whenever possible.
• Take end-to-end ownership of project delivery within the team.
• Maintain and manage technical documentation and address technical debt proactively.
• Participate in the hiring process through tech-fit interviews and technical challenge evaluations.

Requirements:

• 6+ years of overall software development experience.
• Minimum 5 years of experience with Java and Spring Boot.
• Strong understanding and hands-on application of design patterns.
• Practical experience with testing practices (unit, integration) using tools such as JUnit, Mockito, TestContainers.
• 4+ years of experience with AWS Services, Kubernetes, event-driven architectures (Kafka or ActiveMQ), Spring Boot, SQL, and NoSQL.
• Excellent communication skills with the ability to articulate challenges and solutions clearly.
• Proven team player who collaborates effectively and supports shared goals.
• Strong critical thinking and problem-solving skills, with the ability to analyze production issues and design robust solutions (highly desirable).
• Proactive in supporting teammates and driving technical improvements (strongly preferred).
• High responsibility when working with payments, as this is a critical, core functionality for the company.

Onicore is a FinTech company specializing in developing products for cryptocurrency operations. We strive to make crypto convenient and understandable for everyone.
 
And now we are looking for a talented and experienced Java Team Lead to join our team. If you’re passionate about working with the latest technologies, contributing to exciting product developments, and collaborating with an awesome team, we want to hear from you!
 
Your Key Duties:

• Design, develop, and maintain high-performance, scalable Java-based applications in the FinTech domain.
• Implement and optimize multithreaded and concurrent solutions, ensuring thread safety and system reliability.
• Build and maintain microservices using the Spring ecosystem.
• Ensure database efficiency, including query optimization, proper indexing, and transaction handling.
• Evaluate and improve application performance, conduct profiling sessions, and resolve bottlenecks.
• Design and implement synchronous and asynchronous integrations with internal and external systems.
• Participate in architectural discussions, propose improvements, and drive technical initiatives.
• Collaborate closely with product managers, architects, and QA engineers to deliver business-critical solutions.
• Write clean, maintainable, and well-tested code following best practices.
   

Your Skills:

• 5+ years of professional experience in Java development.
• Strong expertise in Java 17+ (knowledge of modern language features, streams, lambdas, functional programming concepts).
• Deep understanding of core Java:
• Collections Framework, Generics, Streams, Functional Interfaces
• Concurrency utilities (Executors, CompletableFuture, Fork/Join, Locks, Atomics, etc.)
• Proven experience with the Spring ecosystem: Spring Boot, Spring Data (JPA/Hibernate), Spring Security, Spring Cloud (microservices).
• Solid understanding of databases (SQL and/or NoSQL), including:
• Transactions, isolation levels, and locking mechanisms
• Query optimization and indexing strategies
• Hands-on experience with multithreading and concurrency, including race conditions, deadlocks, synchronization, and strategies to avoid them.
• Proficiency in synchronous and asynchronous communication: REST, messaging systems (Kafka, RabbitMQ, etc.), event-driven architectures.
• Experience working on FinTech or financial services projects.
• Strong focus on performance evaluation, scalability, and reliability.
• Strong problem-solving skills, ability to work independently, take initiative, and drive solutions proactively.
• Self-driven and responsible, capable of working with minimal supervision.
• Proactive, solution-oriented mindset.
• Team player with a collaborative attitude.
   

Nice to have:

• Experience with Kubernetes, Docker, and cloud-native environments.
• Experience with application profiling and performance tuning:
• Tools such as VisualVM, JFR (Java Flight Recorder), JMC (Java Mission Control)
• Identifying and resolving performance bottlenecks
• Analyzing complexity of SQL queries and optimizing execution plans
• Familiarity with CI/CD pipelines and DevOps practices.
• Knowledge of distributed systems, event sourcing, or CQRS.
   

What’s on us:

— Competitive salary and benefits package.

— Opportunities for professional development and career growth.

— Health insurance.

— Remote work with the possibility to visit our office in Kyiv.

— Space to share your ideas and bring them to life.

Is this all about you? Send us your CV!

Ajax Systems is a full-cycle company working from idea generation and R&D to mass production and sales. We create security solutions for residential and commercial properties, with a portfolio of 280+ devices across intrusion protection, video surveillance, fire safety, and automation. The whole team is in one office in Lviv, all technical and product decisions are made locally.

We’re looking for an Java Developer to join us and continue the evolution of a product that we love: someone who takes pride in their work to ensure that user experience and development quality are superb. You will be able to develop the apps in the best hardware company of Ukraine with around 300M active users around the world. Moreover, very soon you will have a chance to start several new products from scratch.

Required skills:

• 5+ years of commercial experience in backend development with Java in an enterprise environment;
• Strong understanding of Java Concurrency and hands-on experience with concurrent programming in production systems;
• Solid understanding of SOA, microservices, and event-driven architecture;
• Practical experience with cloud computing platforms;
• Experience building and supporting high-load, scalable, and highly available systems;
• Hands-on experience with messaging brokers;
• Strong understanding of modern backend infrastructure, NoSQL, key-value databases, and in-memory storage solutions;
• Practical experience with Docker or Kubernetes;
• Experience with Git, Gradle or othet CI/CD tools;
• Strong knowledge of unit testing and automated testing approaches.

Would be a plus:

• Experience with some of technologies: Redis, Netty, Akka, NATS, AWS, MQTT, Kafka, MongoDB, gRPC.
• Practical experience with Kotlin.

What you will do:

• Design and develop core backend services and data pipelines for the product line;
• Build clean, maintainable, and production-ready code with a strong focus on quality;
• Contribute to backend architecture, drive technical decisions, and document solutions for reliable deployment and operations;
• Ensure proper test coverage with unit and integration tests;
• Take ownership of performance, scalability, and cost efficiency within your domain;
• Maintain production reliability through monitoring, alerting, dashboards, and runbooks;
• Investigate and resolve production issues, including deep-dive analysis of complex cases;
• Work in a strong engineering culture with testing, continuous delivery, and DevOps practices;
• Collaborate closely with product and engineering teams to deliver new features and improve existing services.

Why this role is interesting:

• Opportunity to work on high-load backend systems and distributed architecture;
• Real impact on core product development and architectural decisions;
• Modern technology stack and engineering-driven environment;
• Close collaboration with experienced engineers in a culture that values quality, ownership, and technical excellence;
• Challenging tasks where performance, reliability, and scalability truly matter.

We offer:

• The opportunity to share and implement your own ideas that could impact products and production;
• Work with a motivated team and an environment with a zero-bullshit culture;
• Competitive salary;
• Medical insurance;
• Corporate English classes;
• Compensation for professional training;
• The chance to take part in beta testing of Ajax security systems — receive and test new devices before their release.

Ajax Systems is a Ukrainian success story, a place of incredible strength and energy.
Join us in making Made in Ukraine 🇺🇦 synonymous with reliability.

Requirements:
5+ years of overall commercial software development experience
Java: 4+ years of experience
C++: 2+ years of experience
Scala: 2+ years of experience
В2+ English

Responsibilities:
Own SQL acceleration features end-to-end — from design to implementation and measurable performance impact
Implement and optimize Big Data processing algorithms across Scala, Java, and C++
Develop performance-critical components at the intersection of Big Data and compilers
Work with custom DSL and code generation systems to extend query execution capabilities
Contribute to cross-language integrations (Java  C++ via JNI) and overall system performance improvements

• Project Description:

  One of the world's largest providers of products and services to the energy industry has a need to develop and support enterprise information system in Oil & Gas domain.
  Product being developed is a cloud solution for interpretation of geological and geophysical data. Project is based on SCRUM methodology.
  Our project is stable, long-term and constantly adopts new technologies such as newest Java and Eclipse RCP versions, cloud and GPU computing, microservices architecture and other innovative frameworks.
  Work supposes close cooperation with Customer team located in Houston and following Agile principles.
  Our team is senior, supportive and friendly.
   

• Responsibilities:

  • Collaborate closely with geophysicists, data scientists, and software engineers to translate scientific domain requirements into robust on-prem or Cloud software
  solutions.
  • Design, develop, and maintain high-performance applications for geophysical and geological data analysis, interpretation and visualization (e.g., seismic, horizon,
  fault, velocity model, etc.)
  • Present architectural designs and technical proposals to the architecture review board.
  • Ability to break down development tasks and lay out clear implementation roadmaps.
  • Implement and optimize computation algorithms
  • Design and develop both thin and thick client applications that interact with cloud-based microservices.
  • Ensure high code quality through unit testing, code reviews, security hardening and continuous integration with other domain tools
  • Provide technical support and lead user troubleshooting sessions to resolve issues and ensure smooth operation of DSG application.
  • Mentor junior developers and actively contribute to architectural and implementation decisions.
  • Embrace Agile/Scrum methodologies, delivering and demonstrating working solutions at the end of each sprint
  • Stay current with emerging technologies and trends in geophysical computing and software development.
   

• Mandatory Skills Description:

  6+ years of hands-on Java development experience
  Strong Java Core knowledge
  Experience with desktop development frameworks: Swing, SWT, or Eclipse RCP
  Proven experience designing and building complex systems end-to-end, not just maintaining or extending existing ones
  Practical understanding of multithreaded programming: ability to implement concurrency in code directly, not only through third-party libraries
  Solid knowledge of design patterns and software architecture principles
  Ability to clearly articulate past projects, personal responsibilities, and concrete individual contributions
  Experience working in non-microservices, non-cloud-native development environments (desktop, embedded, or domain-specific platforms)
  Stable career trajectory, no fragmented job history with short tenures

• One of the world's largest providers of products and services to the energy industry has a need to develop and support enterprise information system in Oil & Gas domain.
  Product being developed is a cloud solution for interpretation of geological and geophysical data. Project is based on SCRUM methodology.
  Our project is stable, long-term and constantly adopts new technologies such as newest Java and Eclipse RCP versions, cloud and GPU computing, microservices architecture and other innovative frameworks.
  Work supposes close cooperation with Customer team located in Houston and following Agile principles.
  Our team is senior, supportive and friendly.

• Responsibilities:

  • Collaborate closely with geophysicists, data scientists, and software engineers to translate scientific domain requirements into robust on-prem or Cloud software
  solutions.
  • Design, develop, and maintain high-performance applications for geophysical and geological data analysis, interpretation and visualization (e.g., seismic, horizon,
  fault, velocity model, etc.)
  • Present architectural designs and technical proposals to the architecture review board.
  • Ability to break down development tasks and lay out clear implementation roadmaps.
  • Implement and optimize computation algorithms
  • Design and develop both thin and thick client applications that interact with cloud-based microservices.
  • Ensure high code quality through unit testing, code reviews, security hardening and continuous integration with other domain tools
  • Provide technical support and lead user troubleshooting sessions to resolve issues and ensure smooth operation of DSG application.
  • Mentor junior developers and actively contribute to architectural and implementation decisions.
  • Embrace Agile/Scrum methodologies, delivering and demonstrating working solutions at the end of each sprint
  • Stay current with emerging technologies and trends in geophysical computing and software development.

• Mandatory Skills Description:

  6+ years of hands-on Java development experience
  Strong Java Core knowledge
  Experience with desktop development frameworks: Swing, SWT, or Eclipse RCP
  Proven experience designing and building complex systems end-to-end, not just maintaining or extending existing ones
  Practical understanding of multithreaded programming: ability to implement concurrency in code directly, not only through third-party libraries
  Solid knowledge of design patterns and software architecture principles
  Ability to clearly articulate past projects, personal responsibilities, and concrete individual contributions
  Experience working in non-microservices, non-cloud-native development environments (desktop, embedded, or domain-specific platforms)
  Stable career trajectory, no fragmented job history with short tenures

• Nice-to-Have Skills Description:

  C++ development skills
  Practical experience with the Eclipse RCP framework
  OSGi knowledge
  Oil & Gas domain experience

• Languages:
  • English: B2 Upper Intermediate

YozmaTech isn’t just another tech company – we’re a global team of go-getters, innovators, and A-players helping startups and product companies scale smarter and faster.
We build dedicated development teams across 10+ countries, creating strong, long-term partnerships based on trust, transparency, and real impact.
Here, every idea counts. We value people who are proactive, open-minded, and ready to grow. If you’re passionate about building meaningful products and want to join a team that feels like family – you’ll feel right at home with us.

Our client is an innovative technology company developing a unique solution at the intersection of hardware and cloud software. Their core product combines thousands of IoT devices deployed in the field with a robust, scalable cloud platform. These IoT devices collect and transmit real-time data, which is then processed, analyzed, and visualized using advanced cloud microservices built on Java, Spring Boot, and AWS.

The system is designed for high performance, reliability, and massive scalability, serving a large and rapidly growing customer base. The roadmap includes not only refactoring and upgrading existing systems (such as migrating to newer Java versions and updating dependencies) but also the development of new features and services that directly impact end users.

By joining this project, you’ll have the opportunity to work on both the core infrastructure and innovative new functionalities, making a tangible difference for thousands of customers and devices worldwide.

We Offer:

🔹Opportunity to contribute to an innovative product at the intersection of hardware and software
🔹Friendly team and a culture of collaboration, care, and openness
🔹Ability to influence architectural decisions and processes
🔹Involvement in international projects and professional growth

Key Requirements:
🔹 4 years of commercial experience in Java development (Senior level);
🔹 Excellent knowledge of Spring Boot;
🔹 Experience with AWS (Aurora, Kinesis, SQS, Cognito, Elasticache/Redis, etc.);
🔹 Experience with Kubernetes and microservices architecture;
🔹 Experience with relational databases (MySQL/Aurora);
🔹 Experience with codebase migration, specifically from Java 8 to Java 21, is a strong advantage;
🔹 Ability to analyze and optimize existing code and propose architectural solutions;
🔹 Good English communication skills (for distributed team collaboration);
🔹 Strong soft skills: accountability, initiative, teamwork, openness to feedback, proactivity, ability to see the big picture and suggest improvements;
🔹 Willingness to work in an international distributed team;
🔹 English – Upper-Intermediate or higher.

Will be plus:
🔹 Experience with IoT solutions;
🔹 Experience working in high-load, scalable systems;
🔹 Experience collaborating with QA and contributing to testing processes;

What you will do:
🔹 Participate in refactoring and upgrading existing code, including migration from Java 8 to Java 21 and updating third-party dependencies;
🔹 Develop new features and services as part of the product roadmap;
🔹 Work with a microservices architecture based on Spring Boot;
🔹 Integrate and work with AWS services: Aurora (MySQL), Kinesis, SQS, Elasticache (Redis), Cognito, Kubernetes;
🔹 Analyze and suggest improvements to architecture and processes;
🔹 Be involved in handling production and on-call incidents, and actively engage in product support and development;
🔹 Collaborate closely with QA, developers, and hardware engineers;

We're hiring a Java developer to build ultra-low-latency systems using Aeron and Chronicle.

You will design and optimize high-throughput messaging with Aeron (IPC/UDP, Cluster, Archive), build persistent off-heap data layers with Chronicle Queue and Chronicle Map, and tune JVM performance down to the microsecond.

You bring strong Java (17+), production experience with Aeron or Chronicle Wire & Queue, understanding of mechanical sympathy, lock-free concurrency, off-heap memory, and Linux perf tooling. Trading or market data background preferred.

Bonus: SBE/zero-copy serialization, LMAX Disruptor, kernel bypass (OpenOnload/DPDK), event sourcing, single-writer architectures.

Competitive pay. Hard problems. Microseconds matter.

Project Description:

The SEM product is embedded within the Geosciences Suite of Applications. This application has multiple views consisting of both 2D and 3D visualizations. The current data visualization is not sufficient for what we would like it to be. This role is expected to work with the lead and the product owner to understand the current shortcomings, investigate and research potential solutions, propose these solutions to the teams, and then work on the implementation of the agreed upon work. To get to this stage, the developers will also need to learn the inner workings of the visualization framework within Geoscience.

Responsibilities:

• Design, develop, and maintain graphics-intensive modules within the Geoscience platform using Java and OpenGL.
• Implement advanced 2D and 3D visualization features for seismic, geological, and geospatial data.
• Optimize rendering performance and ensure cross-platform compatibility, particularly in Linux environments.
• Collaborate with geoscientists and software engineers to translate domain-specific requirements into technical solutions.
• Participate in code reviews, testing, and documentation to maintain high-quality software standards.
• Stay updated with the latest developments in graphics technologies and geoscience applications.

Mandatory Skills:

Java

Linux

OpenGL (Open Graphics Library)

Mandatory Skills Description:

• Bachelor's or Master's degree in Computer Science, Geoscience, or a related field.
• 5+ years of professional experience in Java OR C++ development with a focus on graphics programming.
• Proficiency in OpenGL and related graphics libraries for rendering complex datasets.
• Strong experience working in Linux environments, including shell scripting and system optimization.
• Excellent problem-solving skills and the ability to work collaboratively in a multidisciplinary team.

Nice-to-Have Skills Description:

• Experience with geoscience software platforms.
• Familiarity with geoscience data formats and visualization techniques.
• Knowledge of additional programming languages such as Python, Java.
• Understanding of GIS technologies and spatial data analysis.
• Experience with agile development methodologies and version control systems like Git

Languages:

English: B2 Upper Intermediate

Delasport — Implementing Technological Solutions Here and Now.
Delasport is an iGaming Software company providing Sports Betting & Online Casino software, and turnkey B2B solutions. Established in 2010, Delasport delivers a one-stop-shop solution of Sports Betting and Online Casino from a White-Label, with a full range of management services to a Plug&Play iFrame and a complete Turnkey. We are looking for the top talents to join our team in R&D centre in Kyiv.
 

TECHNOLOGY STACK

Microservice architecture, Java 21, Java 25, Spring Boot 3.5+, JPA, JDBC, PostgreSQL, Kafka, Google Cloud Platform, Kubernetes, Docker, Testcontainers, Gradle
 

RESPONSIBILITIES

• Development of new business initiatives, an extension of existing ones
• Taking an active part in improvements and optimizations to the systems
• Resolve technical problems, critical thinking on the development approach
• Be part of a cross-functional team with end-to-end responsibility for the result
   

REQUIREMENTS

• 3+ years of commercial development experience using Java-related technologies
• 1+ years of working experience with API development
• Hands-on experience with microservice architecture
• Ambition to write high-quality code covered with integration tests
• Solid debugging and troubleshooting skills
• Proactive and result-oriented mindset
• Strong problem-solving skills
• Good level of English
   

WHAT WE CAN OFFER YOU

• Modern office in Podil with an uninterruptible power supply and the Internet
• Personal time off (21 business days of paid vacation, paid days on special occasions, sick leaves, emergency days off)
• Public holidays
• Health and life insurance with our broker, available starting from the month following the employee’s start date with the company
• Modern technical equipment
• English courses with native speakers
• Ukraine-based educational programs
• Sports activities reimbursement
• Corporate entertainments
• Happy hours on Fridays
• Gig contract support

We are looking for talented Senior Java Engineer to to join our AI project in Europe.

Our California-based customer is an American global e-commerce leader, one of the most popular and successful websites on the Internet. It provides platform services by connecting millions of sellers and buyers in more than 190 markets around the world. 

Responsibilities:

• Design and develop a robust and extensible Kotlin framework and platform for configuring and managing AI agents
• Write clean, maintainable, and efficient code that complies with our coding standards
• Ensure the performance, quality, and responsiveness of the framework/platform
• Identify and correct bottlenecks and errors
• Help to maintain code quality, organization, and automatization.

• Create and maintain technical documentation for the framework/platform

   

Requirements:

• At least 5 years of proficiency in Kotlin or Java
• Deep experience with the Spring Framework 
• Reactive tools experience (Project Reactor)
• Knowledge of different communication protocols such as REST, GraphQL, gRPC
• Experience with distributed systems
• Familiarity with tracing, metrics and monitoring best practices
• Experience of creating frameworks and platform for other developers 
• Proficiency in Maven or similar tools 
• Familiarity with NoSQL databases 

• Very good spoken and written knowledge of English language (C1)

   

Nice to have:

• Familiarity with GenAI, AI agents, machine learning, and natural language processing concepts is a plus
• Experience with MCP, A2A, RAG is a big plus
• Experience with event-driven architecture
• Experience with Docker and Kubernetes
• Python experience is nice to have
• BSc or MSc in Computer Science, Engineering or relevant field

Overview:
We are looking for a Senior Backend Engineer to lead the development of core backend services within a modern microservice infrastructure that powers mobile and embedded clients. This is a senior, hands-on role with architectural ownership, ideal for an engineer who enjoys building scalable distributed systems, designing secure and reliable APIs, and mentoring other developers. You will drive technical decisions and collaborate closely with architects, frontend engineers, and product teams to deliver future-proof backend solutions.

Responsibilities:

• Lead the design and development of backend services using Java in a Docker/Kubernetes-based environment;
• Drive architectural improvements and establish backend best practices across the platform;
• Design, implement, and optimize event-driven systems based on Kafka;
• Build secure, scalable RESTful APIs for internal and external consumers;
• Design and query complex data models using PostgreSQL, with strong focus on performance and reliability;
• Collaborate closely with frontend and product teams to deliver features end-to-end, from concept to production;
• Ensure system reliability and observability through logging, tracing, and monitoring;
• Enable integrations with data pipelines and ML-powered services as part of data-driven and AI initiatives;
• Mentor junior engineers, conduct code reviews, and support team-wide technical growth.

Requirements:

• 5+ years of professional experience in backend development within microservice and cloud-native environments;
• Strong production experience with Java (e.g., Spring Boot or similar frameworks);
• Python experience is a plus, especially for data pipelines, ML integration, or scripting tasks;
• Deep understanding of:
  • Kafka and event-driven architectures;
  • PostgreSQL, including advanced schema design and query optimization;
  • Secure API design and implementation (OAuth2, HTTPS, mTLS).
• Hands-on experience with Docker, Kubernetes, and CI/CD pipelines in production;
• Proven ability to lead cross-functional technical initiatives and make architectural decisions;
• Demonstrated experience mentoring or guiding less experienced engineers;
• Exposure to video streaming backends or media platforms is a plus;
• Strong interest or background in ML- or data-driven applications;
• Bonus: Experience with observability stacks (e.g., Prometheus, Grafana) or real-time analytics systems.

• Project Description:

  The role is based in Krakow, where you will join an established team already working there, collaborating with colleagues across the globe.

• Responsibilities:

  As a Java Developer at UBS, you will play a key role in designing, developing, and maintaining high-quality software applications. You will collaborate closely with cross-functional teams to understand project requirements, implement solutions, and ensure the successful delivery of projects.
  
  We are looking for someone who can:
  
  • be a good team member who can deliver business value through software
  • enthusiastic about programming, willing to strive for the best, and have a good sense of clean code
  • pick up new knowledge and new technologies, and be able to work independently
  • implement and deliver high-quality software solutions
  • work in an Agile/Scrum development process environment and practice test-driven development (TDD)

• Mandatory Skills Description:

  • A degree in Computer Science, Engineering, or related field.
  • Proven experience as a Java Developer with proficiency in Java programming language, Spring framework and Hibernate.
  • Exposure to cloud technologies, preferably Microsoft Azure, and willingness to gain experience in cloud-based solutions.
  • Experience with messaging systems such as EMS and Kafka for distributed communication and event-driven architectures.
  • Strong understanding of software development principles, design patterns, and best practices.
  • Basic knowledge of Unix systems for troubleshooting and maintenance tasks.
  • Experience writing automated tests using JUnit for functional and integration testing.
  • Proficiency in Git version control system. Good knowledge of git plugins for IDEs, preferably IntelliJ IDEA
  • Excellent communication and collaboration skills.
  • Ability to work effectively in a team environment and independently when required.

• Nice-to-Have Skills Description:

  • Previous work in the financial services or banking industry is considered an asset.

• Languages:
  • English: C1 Advanced

About the role
We are looking for a Middle Java Backend Engineer to join our team and work on developing and supporting backend services.

You will be involved in building REST APIs, working with databases, and integrating with external systems.

Responsibilities

• Develop and maintain backend services using Java and Spring Boot
• Build and support REST APIs
• Work with PostgreSQL (schema design, query optimization, transactions)
• Integrate with external services via HTTP APIs
• Implement authentication and authorization (JWT, role-based access)
• Work with file storage (S3 / MinIO)
• Write tests and support existing functionality

Requirements

• Experience in backend development with Java and Spring Boot
• Experience building and supporting REST APIs
• Good knowledge of Spring Web, Spring Data JPA, Hibernate, Spring Validation
• Practical experience with Spring Security, OAuth2 Resource Server, JWT, role-based access
• Solid experience with PostgreSQL (schema design, query optimization, transactions)
• Experience managing database migrations with Flyway
• Experience integrating external services via HTTP APIs
• Experience working with S3 / MinIO or similar storage
• Experience with testing: JUnit 5, Spring Boot Test, integration tests
• Experience with Gradle, Docker, Git

Nice to have

• Experience with Testcontainers
• Experience with Keycloak or similar IAM / SSO solutions