Freelance Senior Java Full-Stack Developer

adesso Belgium; Brussel; À distance; EUR 70 000 - 110 000; Temps partiel

Avantages offerts par ce poste

Flexible freelance setup

International group

Résumé du poste

adesso Belgium is expanding its talent pool to bring on experienced freelance Java developers for upcoming projects across Belgium and Europe.

In this consultant role, you will blend strategy with execution, shaping architectures, designing and implementing full-stack solutions with Java/Spring Boot and modern front-end frameworks. You will work in an Agile scrum team, use CI/CD pipelines, and leverage AI-assisted tooling to write cleaner code and accelerate delivery.

Qualifications

• Bachelor's or master's degree in computer science, engineering, or equivalent through experience.
• 5+ years of professional experience as a Java developer.
• Strong passion for building high-quality digital solutions and ability to convince customers and colleagues.
• Flexible, structured, and able to adapt within an Agile team.
• Knowledge of modern software architectures (microservices, event-driven, cloud-native).
• Strong, demonstrable experience with Spring Boot, JPA/Hibernate, Jenkins, Maven, Docker, Kubernetes/OpenShift, Postgres, and message brokers.
• Kafka experience is a big plus; Docker/Kubernetes/OpenShift experience required.
• Experience with complex projects, Domain Driven Design/Clean Code/TDD, BPMN & CMMN, OAuth2, or GitHub Copilot is a strong asset.
• Bonus points for Apache Camel and integration wizardry.
• Proficiency with CI/CD, version control (Git), test automation, and monitoring.
• Fluent in French or Dutch (active proficiency), and English.

Responsabilités

• Translate requirements and architecture into technical designs and working software.
• Design, build, test, and maintain full-stack software solutions.
• Implement automated tests as a standard part of every development effort.
• Build robust backend components in Java and Spring Boot; develop frontend with Angular, React, or Vue.
• Introduce new ideas and best practices; use state-of-the-art technology.
• Set up REST APIs according to OpenAPI; ensure stable integration with other systems.
• Work with CI/CD pipelines (Jenkins, Docker, Kubernetes/OpenShift) and ensure code quality via test automation.
• Collaborate in an Agile scrum team with analysts, developers, architects, and designers.
• Align work with the team; communicate progress and technical choices clearly.
• Present solutions to customers and stakeholders; process feedback and defend technical choices.
• Code with AI assistance (e.g., GitHub Copilot) to accelerate development while focusing on architecture.

Connaissances

Java

Kotlin

Spring Boot

JPA/Hibernate

REST

OpenAPI

Git

Jenkins

Maven

Docker

Kubernetes/OpenShift

PostgreSQL

Message Broker

Angular

Kafka

GitHub Copilot

Formation

Bachelor's or Master's degree in Computer Science/Engineering

Outils

GitHub Copilot

OpenAPI tooling

Description du poste

adesso Belgium, who are we? We are an IT (start-up) provider working under the adesso umbrella with proven track record in different industries. The new Belgian entity of adesso is part of the expansion and growth strategy of the adesso group. With more than 10.000 employees spread over 60 locations we are entering an exciting period with our presence in Brussels, the capital of Europe.

We are looking forexperienced freelance Java developersto join our talent pool for upcoming projects with our customers in Belgium.

Your role

In this consultant role, you will combine strategy with execution. You are both a visionary and a doer: from architecture and code reviews to implementation and deployment.

• You translate requirements and architecture into technical designs and working software.

• You are responsible for designing, building, testing, and maintaining full-stack software solutions.

• You implement automated tests as a standard part of every development effort.

• You build robust backend components in Java and Spring Boot, and develop corresponding front-end components in Angular, react or vue.

• You introduce new ideas and best practices and use state-of-the-art technology

• You set up REST APIs according to OpenAPI specifications and ensure stable integration with other systems.

• You work with modern CI/CD pipelines (Jenkins, Docker, Kubernetes/OpenShift) and safeguard code quality through test automation.

• You work independently alongside functional analysts who provide the requirements, alongside developers, architects and designers within an Agile scrum team.

• You continuously align your work with the team and communicate progress and technical choices in a transparent, structured way.

• You present your solutions to customers and stakeholders, process feedback, and defend well-founded technical choices.

• You don't code alone: AI is your daily pair-programming partner, and you know how to wield tools like GitHub Copilot to write cleaner code faster, catch bugs before they hatch, and spend your brainpower on the architecture decisions that actually need a human.

Required Skills & Knowledge:

Java (10+ years) / Kotling - Spring Boot - JPA/Hibernate - REST - OpenAPI - Git - Jenkins - Maven - Docker - Kubernetes/OpenShift - Postgres - Message Broker (e.g. ActiveMQ) - Angular, among others

Your profile

• You hold a bachelor's or master's degree in computer science, engineering, or equivalent through experience.

• You have at least 5 years of professional experience as a Java developer.

• You have a strong passion for building high-quality digital solutions and the ability to convince both customers and colleagues.

• You are flexible, work in a structured way, and can quickly adapt and integrate within an Agile team.

• You have knowledge of modern software architectures (microservices, event-driven, cloud-native).

• You have strong, demonstrable experience with Spring Boot, JPA/Hibernate, Jenkins, Maven, Docker, Kubernetes/OpenShift, Postgres, and message brokers.

• If you've ever tamed a stream of Kafka topics without losing a single message (or your sanity), we want to hear about it - Kafka experience is a big plus.

• Experience with a complex project, Domain Driven Design/Clean Code/TDD, BPMN & CMMN, OAuth2, or GitHub Copilot is a strong asset

• Bonus points if Apache Camel feels like second nature to you - routing messages between systems without breaking a sweat is exactly the kind of integration wizardry we're after.

• Proficiency with CI/CD, version control (Git), test automation, and monitoring too

• You can communicate fluently in French or Dutch (active proficiency), and in English.

Why join adesso Belgium?

• Work in an international group with strong local expertise in Belgium.

• Collaborate with cross-functional teams within the international data & AI adesso community.

• Flexible freelance setup with the support of a growing adesso Belgium community.