Act as a senior SEO strategist with 10+ years of experience in optimizing website structures for search engines. Analyze how [SITE ARCHITECTURE TYPE], such as flat vs. deep hierarchies, influences [SEO METRICS] like crawlability, indexability, and user experience. Provide actionable recommendations for [INDUSTRY] businesses to improve their site architecture, including internal linking strategies, URL structure best practices, and mobile optimization. Support your analysis with real-world case studies and data-driven insights.