You join a multidisciplinary engineering team working on next-generation systems that support real-time intelligence, operational decision-making, and national-scale data processing. You help rebuild a critical legacy platform from VB.NET into a clean, modular PHP application while contributing to complex data logic, hit-generation engines, and integrations across the police technology ecosystem.

You start from an existing VB.NET application, reverse-engineer the logic, and translate it into a modern PHP8+ codebase using Slim and Laravel. You build new components, integrate multi-indexed and graph-based data sources, and apply an API-first approach for all new development. You design, code, test, and review your own work, contributing to continuous improvement and maintainability.

You collaborate with product managers, analysts, hardware and AI/ML teams, and external integrators. You participate in pair programming, review contributions from colleagues, and ensure code meets quality, performance and security expectations.

Key responsibilities

• Understand and refactor logic from a VB.NET legacy application into a modern PHP8+ architecture
• Build clean, secure back-end components using Slim, Laravel or similar microframeworks
• Combine and process multi-indexed datasets using vector or graph-based logic
• Work API-first, design and consume REST interfaces and (optionally) GraphQL
• Apply test-driven development and ensure high testability for all new code
• Deliver full end-to-end features, including QA of your own work
• Collaborate with multidisciplinary teams including hardware, data, AI/ML and UX
• Perform pair programming and code reviews to maintain shared code quality
• Contribute to documentation, continuous improvement and engineering standards
• Work with external vendors whose codebases may not be internally accessible

What are we looking for?

• Bachelor’s degree in Engineering, Computer Science or equivalent experience
• 10+ years of full-stack engineering experience
• Strong experience in PHP, including Slim, Laravel, Symfony or equivalent microframeworks
• Ability to read and understand VB6/VB.NET for legacy migration
• Solid knowledge of JavaScript frameworks (Vue.js preferred)
• Experience with version control (Git, GitLab/GitHub)
• Strong expertise with PostgreSQL, and familiarity with other SQL/NoSQL engines
• Experience with OpenSearch or ELK is highly valued
• Strong knowledge of Linux and shell scripting
• Experience with Kafka, RabbitMQ or similar queueing/brokering technologies
• Security best practices, including JWT, OAuth2 and secure-by-design coding
• Experience with SonarQube or similar code quality tooling
• Knowledge of REST API design; GraphQL is a plus
• Experience with Agile delivery, JIRA/Confluence
• Dutch or French as native language, with passive knowledge of the other; reading knowledge of English

What do we offer?

Start date: 1 December 2025

Duration: Until end 2025 (extensions expected)

Workload: Freelance

Location: Brussels (min. 2 days/week on-site)