What is cohort analysis? Do you use it in your work? Provide examples.

Cohort analysis is a method of analyzing user behavior, where users are grouped into cohorts based on a specific attribute, such as registration date or first use of the product. This allows tracking how the behavior of each cohort changes over time.

In my work, I use cohort analysis to understand user retention, evaluate the effectiveness of product changes, and identify problem areas. For example, one can compare cohorts of users who registered in different months to see how retention rates change after new features are implemented.

Example: if a cohort of users who registered in January shows 40% retention after a month, and a February cohort shows 50%, this may indicate that the changes made in February improved the user experience.