Walmart SDE-3 (Frontend) Interview Experience

Overview

The candidate participated in an interview process for the SDE-3 (Frontend) position at Walmart Global Tech India. The process consisted of three rounds designed to assess problem-solving abilities, JavaScript proficiency, web system design knowledge, and leadership potential. This breakdown offers insights into the expected scope and depth for senior frontend roles.

Interview Rounds

The interview process was structured into three distinct rounds:

Round 1: Problem Solving (DSA)

This round focused on Data Structures and Algorithms, conducted on a coding platform. The interviewer assessed the candidate's speed and clarity of thought. The candidate was required to solve two medium and one hard-level problem.

• Questions:
  • Compare Two Linked Lists: A classic problem focusing on list traversal and equality checks.
  • Longest Substring Without Repeating Characters: Required sliding window optimization.
  • Sliding Window Maximum: Efficient implementation with a deque was expected.

Tip: The candidate should focus on writing clean, optimized code. Explaining the approach while coding helps the interviewer understand the problem-solving process.

Round 2: JavaScript Problem Solving + Web Fundamentals (System Design)

This round assessed real-world frontend engineering depth, covering JavaScript internals, polyfills, and design thinking.

• Key Areas Covered:
  • Deep dive into JavaScript core concepts (closures, event loop, promises, async/await).
  • Implementing polyfills from scratch.
  • Building browser-like features.
  • Discussing frontend system design topics like SSR and performance optimization.
• Questions:
  • Polyfill for Promise.all + Retry Callback: Implementing from scratch with focus on error handling and concurrency.
  • Browser History Feature: Designing methods for navigating back and forward by N steps.
  • Closures and Polyfills: Conceptual and implementation-level questions.
  • Web Performance & SEO: Discussion of Server-Side Rendering (SSR), Largest Contentful Paint (LCP), and SEO optimization techniques.

Tip: The candidate should demonstrate clarity in design trade-offs, particularly around performance, scalability, and maintainability. Understanding browser internals and rendering pipelines is beneficial.

Round 3: Hiring Manager Discussion

This round shifted the focus from problem-solving to understanding technical leadership and impact.

• Topics Discussed:
  • Ownership of frontend projects and leadership of technical initiatives.
  • Tech stack depth: Decisions around React, state management, build tools, and performance optimization.
  • Collaboration with cross-functional teams (design, backend, QA).
  • Managing design systems and ensuring consistency across large-scale applications.
  • E-commerce platform challenges, especially handling data-driven component rendering and personalization at scale.

The manager aimed to evaluate the candidate's ability to scale frontend systems, handle ambiguity, and mentor others.

Tip: At the SDE-3 level, the expectation is architectural maturity, encompassing the ability to guide project direction, not just code.

Key Takeaways

The interview process at Walmart Global Tech India emphasizes a balance of algorithmic skills, frontend depth, architectural thinking, and leadership & collaboration. Candidates should revisit DSA basics (especially sliding window, arrays, and linked lists), master JavaScript internals and practice writing polyfills, and study frontend system design concepts like SSR, caching, hydration, and performance metrics.

Walmart's frontend interview process is designed to identify engineers who can build at scale, optimize deeply, and lead with clarity. The focus extends beyond writing React code to engineering the web at an enterprise scale.