How can you optimize GraphQL queries for performance, especially when dealing with deeply nested data?

To optimize GraphQL queries for performance, use query depth limiting and complexity analysis to avoid costly database operations. You should also use efficient data loading techniques, such as batching and caching at the data fetching layer, to reduce database load. Additionally, consider implementing a persisted queries mechanism, which will store and efficiently retrieve frequently used or expensive queries. This approach will reduce the need for query parsing and validation on each request.