Ericsson India Frontend Engineer Interview: Rounds, Questions and Preparation

What the job involves

Frontend Engineers in global tech build and maintain user interfaces for web applications, often working on products used by millions. At companies like Ericsson India, they focus on creating responsive, accessible, and high-performance UIs for telecom management systems, dashboards, and customer portals. Day to day involves writing clean code, collaborating with designers and backend engineers, and ensuring cross-browser compatibility.

Role and Technical Knowledge

1. 1

   Explain the difference between let, const, and var in JavaScript.

   Cover scoping (block vs function), hoisting, and reassignment rules. Mention temporal dead zone for let and const.

2. 2

   How does the virtual DOM work in React, and why is it useful?

   Describe how React creates a lightweight copy of the real DOM, diffs changes, and batches updates for performance. Contrast with direct DOM manipulation.

3. 3

   What are semantic HTML elements, and why are they important?

   Give examples like header, nav, main, article, and footer. Explain benefits for accessibility, SEO, and code readability.

4. 4

   How would you make a web page responsive for mobile and desktop?

   Mention media queries, flexible grids, relative units, and mobile-first approach. Discuss testing on different viewports.

Practical Scenarios

1. 5

   You need to display a list of telecom network alarms from a REST API. How would you fetch and render them efficiently?

   Discuss using fetch or Axios, handling loading and error states, and rendering with a framework like React. Mention pagination or virtual scrolling for large lists.

2. 6

   A page you built loads slowly on 3G networks. How would you diagnose and improve performance?

   Suggest using Lighthouse, reducing bundle size, lazy loading images, minifying assets, and using a CDN. Mention caching strategies.

3. 7

   How would you ensure your UI works across different browsers, including older versions?

   Talk about feature detection, polyfills, autoprefixer, and testing tools like BrowserStack. Mention progressive enhancement.

4. 8

   You are asked to implement a dark mode toggle. How would you approach it?

   Cover CSS variables, toggling a class on the root element, persisting preference in localStorage, and respecting system preferences via prefers-color-scheme.

Behavioural and HR

1. 9

   Tell me about a time you worked in a team to complete a project. What was your role?

   Use STAR method. Highlight collaboration, your specific contribution, and the outcome. Show adaptability and communication.

2. 10

   Describe a challenging bug you fixed. How did you approach it?

   Explain the debugging process, tools used, and lessons learned. Emphasize persistence and systematic problem-solving.

3. 11

   Why do you want to work as a Frontend Engineer at a global tech company like Ericsson India?

   Connect personal interest in UI/UX with the company's scale and impact. Mention eagerness to learn from large-scale systems and contribute to telecom solutions.

4. 12

   How do you keep your frontend skills up to date?

   Mention following blogs, taking online courses, contributing to open source, and building side projects. Show genuine curiosity.

Problem Solving and Design

1. 13

   How would you design a reusable button component that supports different sizes and colors?

   Discuss props for variant and size, CSS classes or styled-components, accessibility (aria labels), and avoiding prop drilling.

2. 14

   Explain how you would handle state management in a large frontend application.

   Compare local state, Context API, and libraries like Redux or Zustand. Mention when to use each and trade-offs.

3. 15

   What steps would you take to ensure your application is accessible to users with disabilities?

   Cover semantic HTML, ARIA roles, keyboard navigation, color contrast, and testing with screen readers.

4. 16

   Given a UI mockup, how would you break it down into components?

   Talk about identifying reusable pieces, component hierarchy, and data flow. Mention atomic design principles.