Frontend Interview Experience in Mercer Mettl (SDE 2)

Overview

The candidate participated in a 2-hour interview at Mercer Mettl for a Senior Software Engineer position. The round was conducted by the Team Lead and covered a wide range of frontend engineering topics, including JavaScript fundamentals, algorithm design, and system design considerations for building scalable and performant applications. The interview also included discussions around past projects and relevant experience.

Interview Rounds

The interview consisted of a single, comprehensive technical round. The topics covered included:

• JavaScript Fundamentals:
  • Hoisting: The candidate was asked to explain hoisting in JavaScript and provide examples.
  • Temporal Dead Zone (TDZ): The candidate was questioned on the concept of the Temporal Dead Zone.
  • Hoisting Snippets: The interviewer presented multiple code snippets to assess the candidate's understanding of hoisting behavior.
  • call, bind, and apply: A deep discussion on the differences and use cases of these methods, with a particular focus on call.
  • Polyfill for call: The candidate was asked to create a polyfill implementation of the call method.
• Algorithm and Data Structures:
  • Deep Flattening of an Object: The candidate was tasked with writing a function to deeply flatten a nested object.
• Machine Coding:
  • Typeahead Search with Suggestions: The candidate was required to implement a typeahead search component that provides suggestions. The implementation needed to be modular, scalable, and optimized for performance.
    • The candidate encountered challenges in combining Promises (using a dummy Promise for API calls), setTimeout, and debouncing (for which they were asked to create a polyfill).
• Resume Discussion:
  • The interviewer engaged in a detailed discussion of the candidate's resume, focusing on past projects, role-specific experiences, and relevant technical skills.

Key Takeaways

• Mercer Mettl's interview process for Senior Software Engineers involves a thorough assessment of JavaScript fundamentals, problem-solving skills, and system design abilities.
• Candidates should be prepared to implement polyfills for common JavaScript methods and demonstrate a strong understanding of asynchronous programming concepts.
• The machine coding round emphasizes the importance of building modular, scalable, and performant solutions, not just functional code.
• A strong understanding of data structures and algorithms is essential for tackling complex problems.
• Candidates should be prepared to discuss their past projects in detail and articulate their contributions and technical challenges faced.