Senior Software Engineer

Senior Software Engineer (Freelance) – 4 Months – Brussels

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About the Role

We are seeking a Senior Software Engineer (Freelance) to act as the technical and architectural owner of a mission-critical validation engine for our client's Common Data Platform. This is a strategic, long-term project (4 months initial contract, with potential for extension) based in Brussels, designed to ensure the sustainability and effectiveness of a modern data ecosystem. You will be the technical reference point, guaranteeing architectural consistency, stakeholder alignment, and the future-proofing of a core data quality component.

Why This Role Matters

The validation engine is the backbone of data quality and trust within our client's central Data Warehouse, which powers a vast array of Data Marts and Reports. Your leadership will directly impact the reliability, scalability, and performance of the Common Data Platform, supporting business-critical decisions and driving the industrialization of data validation processes. This is your opportunity to shape the future of data quality at scale, collaborating with top-tier talent and stakeholders across the organization.

Key Responsibilities

• Define and own the technical and software architecture of the validation engine (Python / Databricks).
• Establish functional designs in close collaboration with Data Governance, Technical Leads, and Program Management.
• Explore and translate business requirements from diverse stakeholders into robust technical solutions.
• Ensure continuous alignment and consultation with all business and technical stakeholders.
• Supervise and mentor a dedicated developer, providing technical guidance and code reviews.
• Actively participate in testing and validating data products to ensure quality and compliance.
• Challenge and guide technical choices for rule implementation (JSON, SQL, or alternatives).
• Guarantee the performance, robustness, and scalability of the validation engine in a cloud environment.
• Document architecture decisions, standards, and best practices for ongoing and future reference.
• Oversee seamless integration of the validation engine into the Common Data Platform and its pipelines (Azure / Databricks).
• Serve as the go-to technical authority for all topics related to the validation engine.

Technical Skills & Experience

• Master's degree in Computer Science or equivalent.
• Minimum 10 years of experience in software engineering, with a focus on architecture, design, and technical supervision (especially back-end).
• Proven expertise with Python and Databricks (minimum 3 years), including Spark environments.
• Strong background in ETL/ELT processes (8 years).
• Extensive experience in Data Quality and Data Validation (5 years).
• Solid understanding of rule-based approaches and their implementation.
• Deep knowledge of software architecture and design patterns (5 years).
• Experience with Cloud environments, ideally Azure (3 years).
• Ability to document and translate business processes into technical requirements.
• Experience mentoring and challenging developers (Python, SQL, performance optimization).
• Experience in multi-stakeholder or inter-organizational projects is a strong asset.
• Familiarity with BPMN (minimum 3 years).

Language Proficiency

• Excellent command of French, Dutch, and English (active knowledge required).

Other Requirements

• Technical leadership with strong diplomacy and stakeholder management skills.
• Acts as guarantor of technical quality without being hands-on in daily development.
• Rigorous, strategic mindset with a relentless focus on quality and process industrialization.
• Strong affinity for data quality and validation at scale.
• Willingness to work on-site in Brussels at least two days per week (no full remote; telework within Belgium possible).

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