Adaface Sample Frontend Questions

A web app for a popular AI conference (conducted in New York, with attendees from around the world) uses a signup/login page before users can access their dashboard. The signup/login page uses a form for users to input details and submit. The details are then sent to the backend service for processing. All user actions are logged in a log server. Senior Frontend Engineer, Musk, observed patterns in the issues users are facing with the the web app. Here are the two common patterns that Musk observed in the issues that have been occurring for most users:

Which of the following should Musk do to enhance the user experience with the page?
            
            A: Implement validation using JS event listeners on client-side (e.g., on input or change)
            B: Utilize HTML5 built-in form validation attributes (e.g., required, pattern)
            C: Use server-side validation and refresh the page on form submission
            D: Use a serverless function that processes the user’s form details, saves the user’s entries in the database and responds with validation data

A senior front-end engineer is tasked with optimizing the loading speed of a web application. The current bottleneck is the large number of JavaScript files that must be downloaded before the application becomes interactive. The engineer noticed that the browser spends a lot of time parsing and executing the JS code before making the application interactive. Which of the following techniques should the engineer apply to address this issue?