How do you handle analytics when the underlying data changes constantly?

Working with constantly changing external data can make analytics much harder than it looks at first. It isn’t just about getting the data into a warehouse. Freshness, changes in source structure, missing values and historical consistency can all affect the accuracy of reports and dashboards. I’m currently working with ticketsdata, which aggregates publicly available ticket market data and provides reports, analytics and monitoring alongside its data feeds. For those working with external data sources, how do you normally handle these challenges? Do you rely mainly on automated validation and