Scalability is achieved through best practices in data modeling, such as designing star schemas and reducing the number of relationships in the dataset. Power BI development company utilize cloud-based services like Azure to store and process large volumes of data, ensuring the solution can handle increased loads as the business grows. Incremental refresh, DirectQuery, and the use of aggregations further enhance scalability. Power BI development companies also implement modular reporting structures, allowing businesses to add new reports and dashboards as needed without affecting existing performance or data integrity.