Hiring guide for Vue.js Engineers

Vue.js Developer Hiring Guide

Vue.js is an open-source JavaScript framework used for building user interfaces and single-page applications. It was first released in 2014 by Evan You, a former Google engineer. Vue.js allows developers to create web applications with a more simple and flexible API, while still maintaining advanced features required for complex projects. It offers data-reactive components with a simple and flexible API which makes it easier to integrate into projects that use other JavaScript libraries. Vue.js also provides transition effect systems, template logic control, form input bindings among other features that make the development process more manageable and efficient.

Ask the right questions secure the right Vue.js talent among an increasingly shrinking pool of talent.

First 20 minutes

General Vue.js app knowledge and experience

The first 20 minutes of the interview should seek to understand the candidate's general background in Vue.js application development, including their experience with various programming languages, databases, and their approach to designing scalable and maintainable systems.

How would you define Vue.js directives?
Vue.js directives are special attributes with the v- prefix. They are expected to apply special reactive behavior to the rendered DOM. Examples include v-if, v-else, v-show, v-bind, v-on, v-model, etc.
What are Vue.js components?
Components are reusable Vue instances with a name. They are used to create custom elements in Vue.js that can be reused in HTML.
Describe the difference between computed properties and methods in Vue.js.
Computed properties are cached based on their dependencies. A computed property will only re-evaluate when some of its dependencies have changed. On the other hand, a method invocation will always run the function whenever a re-render happens.
How would you handle form input in Vue.js?
Vue.js uses the v-model directive to handle form input and implement two-way data binding. The v-model directive automatically picks the correct way to update the element based on the input type.
What are Vue.js filters?
Filters are used to apply common text formatting. They are denoted by the “pipe” symbol and can be used in two places: mustache interpolations and v-bind expressions.
The hiring guide has been successfully sent to your email address.
Oops! Something went wrong while submitting the form.

What you’re looking for early on

Does the candidate have a strong understanding of Vue.js and its core principles?
Can the candidate solve problems and debug using Vue.js?
Have they demonstrated experience with Vue.js in past projects?
Is the candidate familiar with Vue.js best practices and coding standards?

Next 20 minutes

Specific Vue.js development questions

The next 20 minutes of the interview should focus on the candidate's expertise with specific backend frameworks, their understanding of RESTful APIs, and their experience in handling data storage and retrieval efficiently.

Describe the difference between Vue.js mixins and components.
Components in Vue.js are reusable instances where we can include our code and reuse it wherever we need it in our project. Mixins in Vue.js are a flexible way to distribute reusable functionalities for Vue components. A mixin object can contain any component options.
How would you create a custom directive in Vue.js?
Vue.js allows us to register our own custom directives. We can register a global custom directive with the Vue.directive() function, passing in a name and a definition object.
What are Vue.js lifecycle hooks?
Lifecycle hooks are a window into how the library you're using works behind-the-scenes. Vue.js provides a number of these hooks, allowing you to execute code at various stages of the component's lifecycle, like created, mounted, updated, and destroyed.
Describe the difference between Vue.js instance and Vue.js component.
A Vue instance is the root of every Vue application. The Vue constructor creates a new Vue instance. A Vue component is an instance of a Vue with predefined options. Components are what makes up the different parts of your page and can be reused and imported into your projects.
How would you handle state management in Vue.js?
Vue.js uses Vuex for state management. Vuex is a state management pattern + library for Vue.js applications. It serves as a centralized store for all the components in an application, with rules ensuring that the state can only be mutated in a predictable fashion.
The hiring guide has been successfully sent to your email address.
Oops! Something went wrong while submitting the form.

The ideal back-end app developer

What you’re looking to see on the Vue.js engineer at this point.

At this point, a skilled Vue.js engineer should demonstrate strong problem-solving abilities, proficiency in Vue.js programming language, and knowledge of software development methodologies. Red flags include lack of hands-on experience, inability to articulate complex concepts, or unfamiliarity with standard coding practices.

Digging deeper

Code questions

These will help you see the candidate's real-world development capabilities with Vue.js.

What does this simple Vue instance do?
new Vue({
  el: '#app',
  data: {
    message: 'Hello Vue.js!'
  }
})
This code creates a new Vue instance and targets the HTML element with the id 'app'. It also sets a data property 'message' with the value 'Hello Vue.js!'
What does the v-bind directive do in this code snippet?
The v-bind directive dynamically binds one or more attributes, or a component prop to an expression. In this case, it binds the 'id' attribute of the div to the value of the 'dynamicId' property from the Vue instance.
What will be the output of this Vue method that manipulates an array?
new Vue({
  el: '#app',
  data: {
    items: ['Apple', 'Banana', 'Cherry']
  },
  methods: {
    reverseItems: function() {
      this.items.reverse()
    }
  }
})
This code creates a new Vue instance with a data property 'items' that is an array of fruits. It also defines a method 'reverseItems' that reverses the order of the items in the array. The output would be ['Cherry', 'Banana', 'Apple'] after 'reverseItems' method is called.
What does this Vue code do in relation to threading or concurrency?
new Vue({
  data: {
    count: 0
  },
  created: function () {
    var vm = this
    setInterval(function () {
      vm.count++
    }, 1000)
  }
})
This Vue instance has a data property 'count' initially set to 0. In the 'created' lifecycle hook, it starts a JavaScript interval that increments 'count' every 1000 milliseconds. This demonstrates Vue's reactivity system, as Vue will efficiently update the DOM whenever 'count' changes.

Wrap-up questions

Final candidate for Vue.js Developer role questions

The final few questions should evaluate the candidate's teamwork, communication, and problem-solving skills. Additionally, assess their knowledge of microservices architecture, serverless computing, and how they handle Vue.js application deployments. Inquire about their experience in handling system failures and their approach to debugging and troubleshooting.

What are Vue.js slots?
Slots are a powerful tool for creating reusable components in Vue.js. A slot is a placeholder inside a component that gets replaced with content when the component is used. This allows you to inject content into the parts of a component that you define.
Describe the difference between v-show and v-if directives in Vue.js.
v-if is a directive used to conditionally render a block. The block will only be rendered if the directive’s expression returns a truthy value. On the other hand, v-show toggles the display CSS property of the element. Unlike v-if, the element is always rendered regardless of the initial condition.
How would you handle routing in Vue.js?
Vue.js uses the vue-router library for routing. With vue-router, we can easily create and manage routes in our Vue.js applications. It allows us to map components to routes and create single page applications with ease.

Vue.js application related

Product Perfect's Vue.js development capabilities

Beyond hiring for your Vue.js engineering team, you may be in the market for additional help. Product Perfect provides seasoned expertise in Vue.js projects, and can engage in multiple capacities.