In what situations might using DTO be impractical or undesirable?

Using DTOs (Data Transfer Objects) may be impractical or undesirable in the following cases:

• Simple applications or prototypes: when the data structure is uncomplicated and there is no need for an additional layer of abstraction.
• High frequency of changes: if the model changes often, supporting DTOs can complicate and slow down development.
• Redundancy: if the DTO completely replicates the structure of the domain model without changes, it adds unnecessary code and complicates maintenance.
• Performance: with a large number of DTOs and transformations between them, overhead may occur.

In such cases, it is possible to use domain objects directly or other approaches to avoid unnecessary complexity.