This study investigates the role of Enterprise Architecture (EA) in enhancing business-IT alignment during a large-scale re-engineering project at a European agency. Using a qualitative case study approach, the research analyzes insights from business and IT stakeholders involved in the Surveillance Systems Re-engineering (SSR) project. Focus group sessions were conducted to identify the strengths, weaknesses, and practical recommendations for EA implementation. The findings are organized across four dimensions of alignment: Communication, Governance, Partnership, and IT Scope & Architecture—adapted from Luftman’s maturity model. Results show that EA contributes significantly to mutual understanding, learning acceleration, and strategic alignment but is challenged by complex methodologies, rigid modeling languages, and organizational readiness issues.