**Location:** Brussels, Belgium (Hybrid: 2-3 days remote per week)

**Type:** Freelance Contract

**Experience Level:** Senior / Expert (10 years of experience)

**Languages:** French or Dutch (Professional working proficiency, min. 3/4) **OR** English (Professional working proficiency, min. 3/4)

### **About Smile**

Passionate about tech, digital, and innovation? Join the 1,800 employees at **Smile**, the European leader in open-source integration, spread across 20 agencies in 9 countries.

Collaborative spirit and knowledge sharing are at the heart of our DNA. Our experts push the boundaries of open source every day to build a smarter, more efficient, and more responsible digital world. Here, we don't just follow trends, we create them! Join Smile in Brussels and take part in projects that truly matter!

### **The Opportunity**

On behalf of our client---a major player in their sector based in Brussels---we are looking for an outstanding **Senior API Developer \& Gateway Administrator** on a freelance basis.

In this role, you will act as a key technical expert, driving the development, configuration, and secure deployment of critical API gateways. You will play a vital role in building modern, scalable, and highly secure integration architectures in a collaborative, Agile environment.

### **Your Responsibilities**

* **API Gateway Development \& Configuration:** Design, build, and deploy secure API Gateways, specializing in Axway (or equivalent enterprise suites like Apigee/WSO2).

* **API Design:** Define and implement robust OpenAPI specifications, promoting modern SOA/REST architectural patterns.

* **API Security \& Identity:** Implement and enforce industry-standard security protocols, including OAuth2, JWT, PKI, and secure web services.

* **Vulnerability \& Testing:** Proactively manage API security posture utilizing tools like Snyk and conduct comprehensive web service testing.

* **Modern Lifecycle \& Automation:** Integrate your developments within public cloud infrastructures and CI/CD pipelines, utilizing Git for version control.

* **Agile Collaboration:** Participate actively in Agile ceremonies, using Jira and Confluence for progress tracking and high-quality technical documentation.

### **Your Profile**

* **Experience:** Senior profile with **10 years** of hands-on experience in IT integration, with a strong focus on API gateway development and security.

* **Core Technical Expertise:**

* Solid experience with API Gateway platforms (specifically **Axway** , or alternatively **Apigee** or **WSO2**).

* Mastery of API standards, SOA/REST architecture, and data formats (XML/JSON).

* Strong command of API security frameworks and tools (**JWT, OAuth2, PKI, Snyk**).

* Hands-on experience with **Public Cloud** environments, **CI/CD** automation pipelines, and **Git**.

* Experience in automated web services testing.

* **Methodology:** Proven experience working within an Agile framework utilizing **Jira** and **Confluence**.

* **Languages:** Professional working proficiency (3/4) in either **Dutch** , **French** , or **English**.

### **Why Smile? **

* **Proximity Management:** Our proximity management by peers fosters dialogue and the implementation of a tailored career path.

* **Continuous Growth:** Because the digital sector is in constant motion, Smile is committed to making you an expert in your field, thanks to a comprehensive training offer: access to an e-learning platform, financing of certifications, and dedicated knowledge-sharing tools.

* **Vibrant Community:** Your year will be animated by group and agency events: annual convention, participation in trade fairs, summer party, and both formal \& informal afterworks.

### **The Next Steps **

1. **First Contact:** A phone call to discuss your aspirations and what we can offer you.

2. **Meeting:** An opportunity to get to know each other and explore your professional background.

3. **Business Interview:** A discussion with one of our experts to assess your skills and define your goals.