- Creates the client side of applications.
- Works with AJAX, Comet, server applications.
- Creates OS and application software for custom browser scripts.
- Carries out automation of office applications.
- Deals with the implementation of engines and widgets.
Technical Interview Questions JS
Since this kind of specialist usually has only basic knowledge, often not backed up by practice, the questions here concern the core with a little practice with examples.
- Description of OOP principles, methods, properties of objects, data types in JS.
- What is map, filter, reduce?
- Write options for tasks with add and/or debounce functions.
Questions about React and Redux:
- Purpose of React and Redux.
- Organization of routing.
- General questions about Webpack, gulp, package.json, node.js.
A specialist at this level is expected to be able to perform most tasks and should be able to work without contacting a team lead for about a week.
- What types of tests are there, what libraries are used for this?
- What is XSS and HTTP request, how are they used?
- Characteristics of Observer, Pub / Sub patterns.
- Data types, operators, prototypes, and methods in JS.
Knowledge of functions
- What is memoization?
- Description of the main functions.
- The difference between function and arrow function.
Questions about front-end and layout
- Can the performance of a web page be optimized?
- What are the units of measurement, and what are their characteristics?
- Description and examples of CSS variables.
- Work with customization, rendering, and templating.
Angular and/or React Questions
- Description of the work of custom injectors.
- What is a Renderer service and native methods, when are they applied?
- Application of the Virtual DOM algorithm.
- Enumeration of control libraries to choose from.
Backend and databases
- Characteristics of Node.js and description of the main frameworks.
- Monoliths and microservices: difference, advantages, examples.
- Differences between SQL and NoSQL, solving problems according to the specified parameters.
- Application of JSON and its characteristics.
- What is and where are npm install and npm ci used?
- How is the modular connection of scripts, with examples.
Implementing an array method or writing functions
A specialist who is able to manage processes and build the architecture of the development process.
- General knowledge in TDD and BDD.
- Technology stack for project implementation (examples are selected individually).
- Which frameworks are the most popular and why? Application cases.
- Description of popular patterns and regular expressions with examples.
Front-end and knowledge of Angular and/or React
- Description of how requestAnimationFrame works.
- Methods to avoid loading cached script and style files?
- What are custom decorators, how do I apply them?
- Explain what is the Virtual DOM.
- Is there a difference between createRef and useRef?
- Analysis of the sample code (provided by the interviewer).
- Description of the implementation of features at the choice of the interviewer.
Backend and databases
- Description of RDS and application examples.
- Description of cases of occurrence of SQL Injections. Can they be avoided?
- How to properly design a cluster on MongoDB?
- Description of the basic principles of GraphQL.
- Description of the git-flow methodology.
- What does it mean to create squash commits during rebase?
- General understanding and practical applying of CI / CD.
- How to set up a deployment for multiple environments?
It should be remembered that in IT companies communication and analytical skills, dedication, and high motivation for learning, as well as the ability to look for new approaches in solutions, are well appreciated. Another frequent requirement is knowledge of a foreign language.
Please be aware that the lists of questions in the introductory and technical interviews can significantly vary from company to company. But with a good knowledge of the bark and honesty of the candidate, any interview will be successful. As for the interview evaluating a candidate’s soft skills, we’ll talk about that next time.