API/SOA Architect (Freelance)

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

Type: Freelance Contract

Levels Available: Medior (approx. 3 years exp.) | Senior (approx. 10 years exp.) | Junior (approx. 1 year exp.)

Language Requirements: Fluent in English (3/4 minimum) AND working proficiency in either French or Dutch (3/4 minimum).

About Smile: Why Join Us?

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!

• Peer-to-Peer Management: Our proximity management by peers fosters open dialogue and the implementation of a tailored career path.

• Continuous Learning: Because the digital sector is in constant motion, Smile is committed to making you an expert in your field. Benefit from a comprehensive training offer: access to our e-learning platform, financing of certifications, and robust knowledge-sharing tools.

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

Role Overview

On behalf of our fast-growing division, we are looking for API/SOA Architects at different seniority levels ( Junior, Medior, and Senior ) to join our consultant pool in Brussels.

In this role, you will design, implement, and govern robust API and Service-Oriented Architectures (SOA) for high-impact client projects. You will act as the bridge between business requirements and technical execution, ensuring scalable, secure, and modern integration landscapes.

Key Responsibilities

Depending on your level of seniority (Junior/Medior/Senior), your daily responsibilities will include:

• Architectural Design: Designing and implementing highly scalable, secure, and performant API and SOA architectures using REST, SOAP, and Microservices principles.

• API Development & Governance: Developing APIs (primarily Java-based) and setting up API governance, lifecycle management, and security standards (OAuth2, JWT, Swagger).

• Platform Integration: Configuring and leveraging API Management and Integration platforms (e.g., Axway, Apigee, WSO2, Red Hat Fuse).

• Cloud & Modern Infrastructure: Deploying and managing integration components within public cloud environments (Azure, AWS, or GCP).

• CI/CD & Quality Assurance: Setting up automated deployment pipelines and testing integration flows using tools like SOAPUI, Postman, and ReadyAPI.

• Collaboration: Working within Agile/Scrum teams, documenting architectures in Jira/Confluence, and aligning with diverse business and technical stakeholders.

Your Profile

• Experience: * Junior: ~1 year of experience in API development/design.

  • Medior: ~3 years of experience in API/SOA architecture and development.

  • Senior: 10+ years of deep technical expertise in enterprise integration and architecture.

• Core Technical Skills:

  • Strong background in Java and API/SOA development.

  • Deep understanding of API & Web Service standards: OAuth2, Swagger, JWT, SOAP, WSDL, REST, Microservices .

  • Hands-on experience with API/ESB Platforms: Axway, Apigee, WSO2, or Red Hat Fuse .

  • Familiarity with public cloud platforms ( AWS, Azure, or GCP ).

  • Strong skills in XML and JSON modeling.

  • Experience with testing tools ( SOAPUI, Postman, ReadyAPI ) and CI/CD pipelines.

• Methodology: Comfortable working in Agile/Scrum environments; proficient with Jira and Confluence .

• Languages: Excellent communication skills in English (written & spoken) accompanied by intermediate/advanced professional proficiency in either French or Dutch .

The Recruitment Steps

1. First Contact: A quick phone call to discuss your freelance aspirations, rate, availability, and what we can offer you.

2. Meeting: An opportunity to get to know each other virtually or in person, exploring your professional background and alignment with Smile’s values.

3. Business Interview: A deep-dive technical discussion with one of our senior integration experts to assess your skills and map out your goals.