Apache druid can solve many use cases, a few of them are:-
Apache druid can be used to track user engagement, perform tracking A/B tests, and understand usage patterns.
User behaviour
Druid can be used to analyse network logs to detect cybersecurity threats.
Network flows
Druid can be used to store advertising data and later used to run an advertising campaign, conversion rates, click-through rates, etc
Digital Marketing
Druid can be used to store the application's data and used it analyses the performance of the application over time.
Performance
Druid can be used to store real-time time series data from IoT devices and provide useful information to the user by aggregating and grouping the data.