Popular Interview Question Series: Variations on Asynchronous Map
One of my favorite ‘toy problems,’ often asked in technical interviews during a ‘screening’ phase, is to implement an asynchronous mapping function. This problem can be tricky because it tests your knowledge of asynchronicity and your ability to use callback functions. This knowledge is considered necessary for a web-application engineer — asynchronous programming techniques, event systems, and use of callback functions are standard for building web apps. So, many interviewers use this question to cut to the chase.