Senior Java Developer

Luxoft Poland; Kraków; On-site; PLN 120,000 - 180,000; Full time

Job summary

Luxoft Poland in Kraków seeks an experienced Senior Java Backend Engineer for an enterprise-scale investment banking project. You will design, develop, and maintain backend services using Java 11+ and Spring Boot in a distributed microservices setup.

Collaborate with architects, QA, DevOps, and product owners; implement REST/SOAP APIs with Kafka; BPM workflows (Flowable); and secure systems with OAuth2/JWT.

Qualifications

• Solid JVM experience with Java11+ and design patterns.
• Spring Boot framework experience.
• 7+ years in enterprise-grade application development.
• Experience with distributed microservices and communication patterns.
• Relational and document DB experience: PostgreSQL, MongoDB, Cosmos
• JUnit/TestNG/Mockito/WireMock testing
• OAuth2, JWT, Spring Security
• Agile methodology experience
• Strong communication skills
• Cloud technologies familiarity

Responsibilities

• Design, develop, and maintain enterprise-grade backend services using Java 11+ and Spring Boot.
• Contribute to the design and evolution of distributed microservices architectures.
• Implement and integrate REST and SOAP APIs and event-driven solutions using Kafka.
• Develop and maintain BPM workflows using a BPM engine (Flowable).
• Ensure high standards of code quality by applying SOLID principles, Clean Code, and design patterns.
• Write and maintain comprehensive unit and integration tests using JUnit, TestNG, Mockito, and WireMock.
• Work with relational and document databases (PostgreSQL, MongoDB, Cosmos).
• Implement security and authentication mechanisms using OAuth2, JWT, and Spring Security.
• Collaborate with DevOps on containerization and deployment using Docker and Kubernetes.
• Participate in agile ceremonies and provide technical guidance and code reviews.
• Collaborate with cross-functional teams including QA, DevOps, and product owners.

Skills

Java 11+

Spring Boot

Microservices

PostgreSQL

MongoDB

OAuth2/JWT

Agile

CI/CD

Tools

Kafka

Flowable

Docker

Kubernetes

Job description

You will join a long-term, enterprise-scale project for a global client in the investment banking domain. The project focuses on building and evolving a set of mission-critical backend services that support complex business workflows, regulatory processes, and system integrations across the bank's ecosystem.

The platform is based on a distributed microservices architecture, leveraging Spring Boot, event-driven communication, and BPM-driven process orchestration. The system operates in a cloud-enabled, containerized environment, with a strong emphasis on security, scalability, resiliency, and maintainability.

You will work closely with architects, QA engineers, DevOps, and business stakeholders in an agile setup, contributing not only code but also technical direction, best practices, and mentoring.

Responsibilities

• Design, develop, and maintain enterprise-grade backend services using Java 11+ and Spring Boot


• Contribute to the design and evolution of distributed microservices architectures


• Implement and integrate REST and SOAP APIs and event-driven solutions using Kafka


• Develop and maintain business process workflows using a BPM engine (preferably Flowable)


• Ensure high standards of code quality by applying SOLID principles, Clean Code, and design patterns


• Write and maintain comprehensive unit and integration tests using JUnit, TestNG, Mockito, and WireMock


• Work with relational and document databases such as PostgreSQL, MongoDB, and Azure Cosmos DB


• Implement security and authentication mechanisms using OAuth2, JWT, and Spring Security


• Collaborate with DevOps teams on containerization and deployment using Docker and Kubernetes


• Participate actively in agile ceremonies (refinement, planning, reviews, retrospectives)


• Provide technical guidance, perform code reviews, and advocate for engineering best practices


• Collaborate closely with cross-functional teams, including QA, DevOps, and product owners

Skills

Must have

• Solid experience in JVM programming languages (ideally Java11+) and design patterns


• Frameworks: Spring Boot


• Proven track record of enterprise level application development for 7+ years


• Understanding of distributed microservices architectures and communication patterns


• Experience with relational and document databases (PostgresSQL, MongoDB, Azure Cosmos)


• Testing Frameworks (JUnit, TestNG, Mockito, WireMock)


• Security & Authentication (OAuth2, JWT, Spring Security)


• Experience with Agile mode of working


• Excellent communication and collaboration skills


• Familiarity with Cloud based technologies

Nice to have

• experience in or willing to learn Java reactive programming/ Spring Webflux


• springboot Microservices


• experience with NoSQL databases (ideally MongoDB or CosmosDB)