Senior Java Developer

Luxoft; Kraków; On-site; PLN 180,000 - 320,000; Full time

Job summary

Luxoft is seeking a senior backend engineer in Kraków to design, develop and maintain enterprise-grade Java services using Spring Boot within a distributed microservices framework. The role emphasizes REST/SOAP API design, event-driven patterns with Kafka, BPM workflows via Flowable, and strong security practices with OAuth2/JWT.

You will collaborate with architects, QA, DevOps and product owners in an agile setup, delivering robust, scalable backend solutions and mentoring peers in best

Qualifications

• Solid experience in JVM languages (Java11+), with design patterns.
• Spring Boot framework expertise.
• Enterprise-grade backend development with 7+ years experience.
• Distributed microservices architectures and communication patterns.
• Relational and document databases (PostgresSQL, MongoDB, Cosmos).
• Testing frameworks (JUnit, TestNG, Mockito, WireMock).
• Security & Authentication (OAuth2, JWT, Spring Security).
• Experience with Agile ways of working.
• Excellent communication and collaboration skills.
• Familiarity with cloud-based technologies.

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-driven workflows (Flowable).
• Ensure code quality with SOLID, Clean Code, and design patterns.
• Write unit and integration tests (JUnit, TestNG, Mockito, WireMock).
• Work with PostgreSQL, MongoDB, and Cosmos DB.
• Implement security with OAuth2, JWT, and Spring Security.
• Collaborate with DevOps on Docker/Kubernetes deployments.
• Provide technical guidance, code reviews, and best practices.

Skills

Java 11+

Spring Boot

Microservices

Distributed systems

PostgreSQL/MongoDB/CosmosDB

JUnit/TestNG/Mockito/WireMock

OAuth2/JWT/Spring Security

Cloud familiarity

Agile methodology

Communication & collaboration

Tools

Spring Boot

Kafka

Flowable BPM

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
• Provide technical guidance, perform code reviews, and advocate for engineering best practices
• Collaborate closely with cross-functional teams, including QA, DevOps, and product owners

Mandatory Skills Description

• 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 Skills Description

• experience in or willing to learn Java reactive programming/ Spring Webflux
• springboot Microservices
• experience with NoSQL databases (ideally MongoDB or CosmosDB)