Frontend Engineer Interview Experience @Razorpay

Overview

Razorpay's frontend engineering team plays a crucial role in building user-friendly and responsive interfaces for their suite of products. This document outlines the interview process for a Frontend Engineer role at Razorpay, emphasizing the skills and qualities the company seeks in its candidates. The role focuses on developing scalable and performant user interfaces utilizing modern frameworks such as React, Vue.js, or Angular. A strong emphasis is placed on coding fundamentals, problem-solving abilities, and the creation of seamless, user-centric designs.

Interview Rounds

The interview process consists of four rounds designed to assess the candidate's technical skills, problem-solving abilities, and cultural fit.

Round 1: Online Coding Assessment (90 minutes)

This round, conducted on HackerRank, evaluates the candidate's proficiency in algorithms, data structures, and SQL. The assessment includes:

• DSA Questions:
  • Find the first unique character in a string. The candidate employed a hashmap to efficiently store character frequencies, enabling a single-pass identification of the first unique character.
  • Merge overlapping intervals. The candidate sorted intervals by start time and iteratively merged overlapping ranges.
  • Optimize a sliding window for maximum subarray sum. The candidate utilized a dynamic programming approach similar to Kadane's algorithm.
• SQL Questions:
  • Query for the top 3 products by sales in each category.
  • Find customers with no transactions in the past 6 months.

The candidate demonstrated strong SQL knowledge and efficient problem-solving skills, resulting in a favorable score.

Round 2: Technical Interview I (90 minutes)

This round emphasizes JavaScript fundamentals and frontend problem-solving skills.

• Tasks:

  • Build a debounce function. The candidate effectively explained the use case for debouncing, particularly in search input optimization, and implemented a clean debounce function using closures.

  • Optimize a React component rendering large data. The candidate discussed techniques such as pagination, virtualization (using React-Window), and memoization to prevent unnecessary re-renders and improve performance.

  • Debug a piece of broken React code:

    const [count, setCount] = useState();
    useEffect(() => {
      if (count > 10)
        console.log("High count!");
    }, []);
    

    The candidate identified the missing dependency in the useEffect hook and suggested best practices for managing state updates.

Round 3: Technical Interview II (90 minutes)

This round focuses on system design and frontend architecture.

• Challenge: Design a dashboard for monitoring payment transactions in real-time.
  • Discussion Points:
    • State Management: The candidate proposed using Redux for managing global states and React Query for efficient API handling.
    • Performance Optimization: The candidate suggested lazy-loading charts and using web workers to handle intensive computations.
    • Component Architecture: The candidate detailed the separation of components into reusable, container, and presentational types.
    • Testing Strategy: The candidate emphasized the importance of unit testing with Jest and integration testing with Cypress.

Round 4: HR Round (30 minutes)

This final round assesses the candidate's cultural fit and long-term alignment with Razorpay.

• Key Questions:
  • Why do you want to work at Razorpay?
  • How do you handle tight deadlines?
  • Share an experience where you faced conflict within a team.

Key Takeaways

• Technical Proficiency: A strong understanding of JavaScript and React fundamentals, including hooks, state management, and lifecycle methods, is essential.
• Problem-Solving Skills: Candidates should be prepared to solve DSA and SQL problems relevant to frontend roles.
• System Design Knowledge: Familiarity with system design concepts for frontend-heavy applications is crucial.
• Cultural Alignment: Demonstrating an understanding of Razorpay's engineering principles and a user-first approach is important.

The candidate showcased a robust combination of technical expertise and problem-solving skills, positioning them as a potentially valuable asset to Razorpay's engineering team. The interview process underscores Razorpay's dedication to recruiting engineers who possess both technical depth and a commitment to user-centric design.