How does AngularJS handle large-scale digest cycle performance issues?

AngularJS performance issues arise from excessive watchers in the digest cycle, which can be mitigated using one-time bindings and scope isolation.

The digest cycle runs dirty checking across all watchers in $scope hierarchy. In large apps, this becomes O(n) per cycle and degrades performance. Optimization requires reducing watchers, using one-time bindings (::), avoiding deep watches, and breaking scope inheritance chains. Architecture-wise, splitting modules and using component-based directives helps reduce global digest pressure.