Complex sentence: Organizations also use RUM to test website or application changes prior to deployment by monitoring for errors or slowdowns in the pre-deployment phase, they may also use it to test changes within the production environment, or to anticipate behavioural changes in a website or application.
Split into simpler sentences: Organizations also use RUM to test website or application changes prior to deployment by monitoring for errors or slowdowns in the pre-deployment phase. They may also use it to test changes within the production environment, or to anticipate behavioural changes in a website or application.