Senior Full Stack Java Developer - Freelance

Freelancer, Full-time · Diegem

Opportunity

Join ILIAS Solutions and contribute to making mission-critical products for the defense industry. We are seeking an experienced Senior Full Stack Java Developer to join our Data Platform team within the Defense Capability Management unit.

In this role, you will work autonomously to design secure, reliable, and scalable applications that support vital operations. If you are a strong communicator ready to apply your skills in Java and Spring Boot to high-stakes challenges, we want to meet you.

Your mission

Key Responsibilities:

Design, develop, and maintain full-stack applications using Java and Spring Boot
Write clean, maintainable, and well-tested code
Work with relational databases (PostgreSQL, Oracle DB, SQL Server) to design schemas, write queries, and ensure data integrity
Integrate and manage object storage systems (MinIO)
Collaborate with data teams on Apache Spark and Python based integrations
Participate in code reviews, technical discussions, and architectural decisions• Ensure applications are secure, reliable, and scalable
Contribute to team knowledge sharing
Troubleshoot and resolve complex technical issues across the full stack

Your capabilities

Required Technical Skills

Backend Development

Java – Advanced proficiency with modern Java
Spring Boot – Extensive experience building RESTful APIs
Database Management – Strong SQL skills with hands-on experience in:
- PostgreSQL
- Oracle Database
- SQL Server
Object Storage – Experience with MinIO or similar S3-compatible storage solutions

Frontend Development

Solid foundation in HTML, CSS, JavaScript, JSP, and Thymeleaf
React experience is a plus

Data Processing & Analytics

Experience with distributed data processing using Apache Spark
Python experience is a plus

Additional Technical Requirements

RESTful API design and implementation
Version control systems (Git)
Build tools (Maven)
Container technologies (Docker preferred)
Testing frameworks (JUnit, etc.)

Required Experience & Qualifications

Bachelor’s degree in Computer Science, Software Engineering, or equivalent experience
5+ years of professional software development experience
Proven experience with Java and Spring Boot
Proven experience working with multiple database systems
Experience with both SQL and NoSQL databases
Strong understanding of the software development lifecycle and agile methodologies

Personal Attributes

Independent Worker – Able to take ownership of projects and work with minimal supervision
Team Player – Collaborative mindset with excellent communication skills
Problem Solver – Strong analytical and troubleshooting capabilities
Adaptable – Comfortable working with diverse technologies and evolving requirements
Quality-Focused – Writes clean, maintainable, well-documented code
Continuous Learner – Passionate about staying current with technology trends and best practices

Land @ILIAS

Exited and ready to explore how you could fit in?
Apply directly or reach out to youness.kaissi@ilias-solutions.com for any questions.
we are thrilled to get to know you!

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About us

ILIAS Solutions offers exciting opportunities to shape the future of armed forces operations. As a global leader in defense logistics software, we empower military commanders worldwide to optimize operations, training, and missions. Our innovative platform covers the entire armed forces value chain, ensuring efficient execution and capturing vital information.

As we continue to grow, we are looking for talented reinforcement who will make a difference every day.
Join our international team and make an impact on global security.

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We are looking forward to hearing from you!

Thank you for your interest in ILIAS. Please fill out the following short form. Should you have difficulties with the upload of your data, please send an email to hr@ilias-solutions.com.