This question is helpful in assessing foundational coding knowledge. There are several possible answers, so listen for thorough responses that demonstrate an understanding of monolithic versus microservice architectures. What to look for:

• The applicant’s familiarity with coding
• The applicant’s understanding of the pros and cons of different approaches to architecture
• An ability to articulate how to transition from monolithic to microservice

Asynchronous programming permits multiple concurrent operations, and it is a good match for JavaScript programs. This question assesses general coding knowledge, as well as specific understanding of JavaScript. What to look for:

• An ability to articulate the difference between synchronous and asynchronous programming
• The impact of asynchronous programming on user interfaces
• An understanding of blocking and the subsequent impact on performance

This question is helpful in learning whether the applicant has experience and expertise in JavaScript. Prototypal inheritance is easier and more flexible than classical inheritance, which makes it the preferred method for experienced JavaScript coders. What to look for:

• A preference for prototypal inheritance and composition
• An ability to articulate the reasons for this preference
• References to functional inheritance, concatenative inheritance, prototype delegation and object composition

How applicants answer this question gives you insight into their experience with JavaScript. There are very few instances when classical inheritance makes sense, and the applicant might say there are none at all. A “no” answer is preferable to a long list of appropriate circumstances, as these are typically based on misinformation. What to look for:

• Classical inheritance is never or almost never the right choice
• Applicants’ ability to articulate reasons for their responses
• Applicants’ ability to defend their reasoning with logic

Functional programming is a fundamental principle in current JavaScript use. Applicants’ ability to answer this question fully gives you assurance of their foundational knowledge. What to look for:

• Mention of function purity and side effect avoidance
• Ability to provide examples of functional programming languages
• Ability to identify the features of JavaScript that enable functional programming

Any applicant with JavaScript experience has used one of these styles and therefore should be able to offer some thoughts on the pros and cons of each. This question assists you in measuring the depth of the applicant’s experience with JavaScript. What to look for:

• An ability to articulate advantages and disadvantages of either method
• Mention of the issues that result from shared resources
• An understanding of how functional programming simplifies applications

The applicant’s ability to answer this question demonstrates deep understanding of the important foundational principles of JavaScript. Candidates who are unfamiliar with these terms may not have the experience required to be successful in the position. What to look for:

• Ability to define the two concepts in a clear, concise manner
• Ability to articulate the difference between the two concepts
• Mention of example frameworks

Boolean logic is an essential part of JavaScript infrastructure and governs how programmers write code. It guides the structure of JavaScript and explains the rules that keep code consistent. Anyone who uses JavaScript in their role should have a strong understanding of the theory and logic behind the code they write. This question helps the interviewer identify the comprehension level of each applicant and select candidates who have a strong understanding of both the JavaScript framework and its potential applications. A good answer will include:

• Definition of Boolean
• Example of Boolean terms
• Understanding of how Boolean operations influence their work