PostgreSQL 9.3 introduced lateral joins, a powerful feature enabling complex queries that were previously achievable only with procedural code, such as PL/pgSQL. Lateral joins function like SQL foreach loops, allowing subqueries to reference columns from preceding FROM items, which significantly enhances query efficiency and flexibility. This feature is particularly beneficial for analyzing conversion funnels, as demonstrated through a case study of optimizing a landing page for increased signups. By using lateral joins, one can efficiently track user interactions across different stages, such as homepage views, demo usage, and credit card entries, without resorting to lengthy SQL queries or external scripting languages. Furthermore, lateral joins facilitate exploratory data analysis and can be integrated into user-friendly interfaces, allowing non-technical users to gain insights. The use of indexing, particularly on SSDs, can further optimize query performance. This new capability in PostgreSQL opens up opportunities for detailed analysis and decision-making directly within the database, highlighting its value in product analytics and data science applications.