Recently, I interviewed for the MTS3 (Member of Technical Staff — UI) position at Nielsen. The process consisted of three rounds, focusing on JavaScript fundamentals, React machine coding, data structures, system design, and discussions on real-world architecture.

Overall, the interview was well-structured and leaned heavily toward practical frontend engineering skills, rather than purely theoretical questions. Below is a detailed breakdown of each round and what you can expect.

🔹 Round 1 — Technical + Machine Coding

The first round covered core JavaScript concepts, React problem-solving, and DSA fundamentals.

1️⃣ Keyify a JavaScript Object

I was asked to write a function that transforms an object into a specific keyed structure.
This tested:

• Object traversal
• Handling nested objects
• Understanding of immutability
• Clean and readable JavaScript logic

Tip: Be comfortable with Object.keys, Object.entries, recursion, and edge cases.

2️⃣ Folder Structure Like VS Code (React — Machine Coding)

This was a machine coding round where I had to implement a VS Code–like folder/file explorer in React.

Key expectations:

• Recursive rendering of folders/files
• Expand/collapse functionality
• State management
• Clean component design

Important concepts tested:

• Recursive React components
• Conditional rendering
• Component reusability
• Performance awareness

This round clearly evaluates real-world React thinking, not just syntax.

3️⃣ LeetCode — Clone Graph (Medium)

LeetCode Problem:
👉 https://leetcode.com/problems/clone-graph/

This question tested:

• Graph traversal (DFS / BFS)
• Handling cyclic graphs
• Deep copy concepts
• HashMap usage for visited nodes

Strong understanding of graphs and recursion is essential for MTS-level roles.

🔹 Round 2 — EM (Engineering Manager) Round

This round was more discussion-oriented, focusing on ownership, design thinking, and the experience.

1️⃣ Resume & Project Discussion

The EM went deep into:

• My recent projects
• My role and contributions
• Challenges faced and how I solved them
• Trade-offs and decision-making

Be prepared to explain why you chose a solution, not just what you built.

2️⃣ High-Level Design (HLD)

I was asked to design a system at a high level, focusing on:

• Component interaction
• Data flow
• Scalability considerations
• UI + backend communication

This round checked:

• System thinking
• Clarity of communication
• Ability to break down complex systems

🔹 Round 3 — Director Round

The final round was with a Director, and it focused on architecture, impact, and depth of experience.

1️⃣ MFE (Micro-Frontend) Architecture of Current Project

I explained the Micro-Frontend architecture used in my current project, covering:

• Why MFE was chosen
• Frameworks used
• Module federation integration strategy
• Deployment and versioning challenges
• Pros and cons of MFE

This round tested real-world architectural maturity.

2️⃣ Progress Bar with Dynamic Content in React

I was asked to design and explain a progress bar component that:

• Updates dynamically based on content or API response
• Handles loading states
• Is reusable and configurable

Key areas evaluated:

• React hooks usage
• Component design
• Handling async data
• UI/UX considerations

Outcome

After successfully clearing all three rounds, I received a positive result and cracked the Nielsen MTS3 UI interview 🎉.

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The process was challenging, practical, and very relevant to real-world frontend engineering, especially at a senior/MTS level.

Written by Diptom Saha