This article explores the architecture, real-life challenges, and best practices in integrating Power BI with Azure Data Lake to build scalable reporting systems. Based on hands-on experience as a data analyst, the article provides insights into data architecture, role-based security (RLS/OLS), performance optimization, and addresses real-world problems faced during the implementation. A visual diagram illustrates the data pipeline, and practical examples highlight solutions to challenges such as data refresh bottlenecks, large dataset modeling, and user-level access restrictions.