IT Technical Lead – Selligent & .NET Legacy

For one of our clients in the telecommunications sector and located in Brussels, we are looking for an IT Technical Lead.

Role overview

We are seeking a highly analytical and deeply technical Senior Software Engineer to lead the reverse-engineering and documentation of our legacy marketing automation infrastructure built on Selligent Campaign. Due to the integration of this historical platform with the Microsoft ecosystem, the consultant will dive into legacy source code, dissect complex database logic, and map undocumented system dependencies. The primary goal is to comprehend how things work under the hood to facilitate system modernization and data migration.

Key responsibilities

• Code decompilation & analysis: analyze, debug, and reverse-engineer legacy Windows-based desktop clients, backend automation utilities, and services built on the Microsoft .NET framework (C#).
• Database logic deconstruction: dissect heavily customized relational database architectures within Microsoft SQL Server, interpreting hundreds of complex Transact-SQL (T-SQL) queries, nested stored procedures, and triggers.
• Script deciphering: unpack and translate proprietary Selligent Expression Language scripts utilized within dynamic emails, landing pages, and web forms into universally understood pseudocode or technical documentation.
• Architecture mapping: discover, map, and document hidden system dependencies, integrations, and data flows between Selligent, internal custom middleware, and third-party APIs (SOAP/REST).
• Modernization blueprinting: collaborate with system architects to convert findings into functional requirements, data dictionaries, and structural maps to ensure a risk-free future migration.

Required skills & qualifications

• The core stack: 8+ years of experience in the Microsoft ecosystem, specifically advanced backend development using C#, .NET Framework, WinForms, and Windows Services.
• Database expert: mastery of Microsoft SQL Server and T-SQL. Highly proficient in reading, optimizing, and rewriting complex database architecture and legacy stored procedures.
• Selligent experience is a high plus: prior exposure to or direct development experience with Selligent Campaign (legacy/on-premises version) is highly advantageous.
• Reverse engineering mindset: proven experience or strong aptitude for reverse engineering codebases lacking documentation.
• Web server architecture: practical knowledge of how legacy web architectures interact with Microsoft Windows Servers.
• Can-do attitude, ability to work within a tight planning schedule, natural curiosity and passion for problem-solving, excellent communication and documentation skills.

Attitudes

• Organized.
• Strong communication skills.
• Assertive.
• Autonomous.
• Leadership capabilities.

Languages

• English.
• French and/or Dutch.