A Distributed cache stores data in a shared location that can be accessed by multiple application instances. This allows multiple nodes of an application to share cached data, improving performance and reducing redundancy.

To efficiently extract specific properties from objects using destructuring assignment in JavaScript, you would use the syntax const { prop1, prop2 } = sourceObject;. This assigns the values of prop1 and prop2 from sourceObject to the corresponding variables. To handle non-existent properties, you can provide default values like const { prop1 = defaultValue1, prop2 = defaultValue2 } = sourceObject;. The other options are not correct ways to achieve this task.

In a sharded database architecture, a central coordinator (Option 2) often handles updates that affect multiple shards. Each shard (Option 3) independently handles updates for its own data, but coordinated updates across shards typically require a central component. Options 1 and 4 are not common methods for handling updates in sharded databases.

To publish a package to the NPM registry, you should use the npm publish command. This command packages and uploads your module to the NPM registry, making it available for others to use and install. Options 1, 3, and 4 are not valid commands for publishing packages and might lead to errors.

Optimizing database queries can significantly reduce response time by minimizing the number of database calls, reducing data retrieval, and improving the efficiency of data fetching, ultimately leading to faster responses. The other options either misrepresent the impact of query optimization or provide irrelevant information.

When working with file operations in Node.js using the fs module, handling asynchronous errors is crucial. Asynchronous file operations can fail due to various reasons such as file not found, permission issues, or disk full errors. Proper error handling ensures data integrity and prevents unexpected crashes in your application.

In semantic versioning, the 'minor' version should be incremented when new features or functionality are added in a backward-compatible manner. This indicates to users that they can safely update to the new version without worrying about breaking changes.

To optimize the rendering performance of template engines like EJS and Pug, enabling caching is a common approach. This allows the templates to be compiled once and reused, reducing rendering time. Additionally, minimizing template complexity and avoiding synchronous rendering can also improve performance. However, completely avoiding template engines may not be practical in many web applications.

The primary role of the app object in an Express application is to handle routing and middleware functions. It defines the routes for handling different HTTP requests (GET, POST, etc.) and can use middleware to add functionality to these routes, such as authentication or error handling. The other options do not accurately describe the role of the app object in Express.

A primary feature of testing frameworks like Mocha or Jest is Test Automation. These frameworks allow developers to write and run automated tests to verify that their code works correctly. This includes unit tests, integration tests, and more.