Java Backend Engineer - RESTful APIs & Enterprise Systems

Bank Julius Bär & Co. Ltd.; Comunidad de Madrid; On-site; EUR 55,000 - 90,000; Full time

Job summary

Bank Julius Bär & Co. Ltd. in Madrid seeks a skilled Java Backend Engineer to develop, enhance, and maintain a critical enterprise platform built on Java/Jakarta EE.

You will work with cross-functional teams to deliver robust backend and frontend solutions and ensure quality through automated testing. The role emphasizes REST API design, Oracle database work, performance tuning, and strong collaboration within Agile squads.

Qualifications

• Strong hands-on Java development experience.
• Experience with Java/Jakarta EE, JPA/Hibernate, and Maven-based apps.
• Experience building and consuming RESTful APIs.
• Working knowledge of Oracle databases, SQL and data persistence concepts.
• Understanding of software design principles and design patterns.
• Experience with automated testing (JUnit, Mockito).
• Familiarity with source control and collaborative workflows.
• Strong problem-solving and collaboration in Agile teams.
• Good communication and team-oriented mindset.
• Ability to work across backend and frontend in a full-stack capacity.

Responsibilities

• Develop and maintain backend applications using Java 21, Jakarta EE, JPA/Hibernate, and Maven.
• Design and implement REST APIs and integrate with internal/external systems.
• Contribute to enterprise integrations using SOAP, JMS, and messaging tech.
• Collaborate with product owners, analysts, and architects to translate requirements into technical solutions.
• Develop Oracle-based data models, queries, and performance improvements.
• Write clean, testable code following engineering standards and best practices.
• Create and maintain unit/integration tests and ensure test coverage.
• Troubleshoot defects, performance issues, and production incidents.
• Contribute to observability, monitoring, and continuous improvement initiatives.
• Support deployment, testing, and release activities across environments.

Skills

Java development

Jakarta EE

JPA/Hibernate

REST APIs

Oracle SQL

Software design principles

Unit testing

Mockito

Source control

Agile

Full-stack

Communication

Tools

JUnit

Mockito (tool)

Job description

Bank Julius Bär & Co. Ltd. in Madrid seeks a skilled Java Backend Engineer to develop, enhance, and maintain a critical enterprise platform built on Java/Jakarta EE.

You will work with cross-functional teams to deliver robust backend and frontend solutions and ensure quality through automated testing. The role emphasizes REST API design, Oracle database work, performance tuning, and strong collaboration within Agile squads.