Lead Java Developer – Payments, Kafka & Spring Boot

Ubique Systems; Amsterdam; On-site; EUR 90,000 - 130,000; Full time

Job summary

Ubique Systems seeks a senior Java developer with team leadership experience to drive end-to-end Java applications. You will lead cross-functional collaboration with Business, Architecture, Ops and Platform teams and own back-end design, implementation and integration using Java 21, Spring Boot, Kafka, and Cassandra.

The role emphasizes strong OOP, multithreading, and unit testing with JUnit/Mockito, with a focus on secure, scalable payments-related back-end services and REST MVC patterns.

Qualifications

• Experience leading a team for 2 complete Java development cycles.
• Experience handling large teams and collaborating with Business, Architecture, Ops and Platform teams.
• Strong knowledge of Java 21 and object-oriented concepts.
• Experience with Kafka and messaging queues.
• Experience with Cassandra databases and SQL.
• Design, develop, and maintain advanced Java-based back-end applications.

Responsibilities

• Lead a team and collaborate with cross-functional groups (Business, Architecture, Ops, Platform).
• Design, develop, and maintain Java-based back-end applications following standards.
• Document software designs, technical specifications, and code changes.
• Assess technical risk and debts and ensure integration quality.
• Perform unit testing with JUnit/Mockito and ensure robust code.

Skills

Team leadership

Java development

OOP

Lambda expressions

Streams API

Multithreading

Integration

Tools

Kafka

Spring Boot

JUnit/Mockito

Cassandra

SQL

Job description

Ubique Systems seeks a senior Java developer with team leadership experience to drive end-to-end Java applications. You will lead cross-functional collaboration with Business, Architecture, Ops and Platform teams and own back-end design, implementation and integration using Java 21, Spring Boot, Kafka, and Cassandra.

The role emphasizes strong OOP, multithreading, and unit testing with JUnit/Mockito, with a focus on secure, scalable payments-related back-end services and REST MVC patterns.