With the appearance of Signals, is it still necessary to specify the Change Detection strategy?

With the introduction of Signals in Angular, the approach to updating the UI has become more reactive and efficient. Signals allow tracking data changes at a lower level and automatically update related components.

Nevertheless, the Change Detection strategy (ChangeDetectionStrategy) remains relevant and useful. It manages how Angular checks for changes in components:

• Default — Angular checks the component and all its descendants on every change detection cycle.
• OnPush — Angular checks the component only when input data changes or explicit events occur.

Signals and Change Detection address similar but not identical tasks. Signals optimize reactivity at the data level, while the Change Detection strategy manages the checking of components in the tree.

Therefore, Signals do not eliminate the need to specify a Change Detection strategy. Instead, they can be used together to achieve maximum performance and control over UI updates.