Behavioral data collection is essential for understanding user interactions with products and creating personalized customer experiences. This guide explores the technologies and tools available for collecting such data, focusing on CDI (Customer Data Infrastructure) and CDP (Customer Data Platform) systems, as well as ELT (Extract, Load, Transform) tools. CDI is designed for gathering data from primary sources like web and mobile apps, while CDP adds a layer for identity resolution and audience syncing. ELT tools, like Airbyte, Fivetran, and Stitch, are better suited for extracting data from secondary sources such as third-party tools. Product analytics tools, including Amplitude and Mixpanel, also play a role in data analysis and collection. The guide emphasizes the importance of setting up a data warehouse to store all collected data and advises against building custom tracking solutions due to maintenance challenges. Collaboration with stakeholders is crucial when deciding on event tracking and data destinations.