Nykaa Software Engineer Interview: Rounds, Questions and Preparation

What the job involves

Software Engineers at Indian unicorns and high-growth startups like Nykaa build and maintain scalable web and mobile applications that power e-commerce, fintech, or consumer platforms. Day to day, they write clean code, debug production issues, collaborate with product and design teams, and optimise systems for performance and reliability under heavy traffic. Freshers typically start with feature development, bug fixes, and writing tests, gradually taking ownership of small modules.

Role and Technical Knowledge

1. 1

   Explain how you would design a database schema for an e-commerce platform like Nykaa that handles products, users, orders, and reviews.

   A strong answer covers normalisation, primary and foreign keys, indexing for search, and handling one-to-many and many-to-many relationships. Mention trade-offs between SQL and NoSQL for product catalogues.

2. 2

   What is the difference between a process and a thread, and how does it matter for a high-traffic web application?

   Explain memory sharing, context switching, and concurrency. Relate it to handling multiple user requests efficiently in a server environment.

3. 3

   How would you optimise a slow SQL query that fetches product listings for a flash sale?

   Cover indexing, query execution plans, avoiding SELECT *, caching, and pagination. Mention denormalisation or read replicas for read-heavy workloads.

4. 4

   Explain RESTful API design principles and how you would version an API for a mobile app and a web app.

   Discuss resource-based URLs, HTTP methods, status codes, and statelessness. For versioning, mention URL versioning or header versioning and backward compatibility.

Practical Scenarios

1. 5

   You are asked to add a new feature to an existing codebase you have never seen. How do you approach it?

   Describe understanding the requirements, reading documentation, exploring the code structure, writing a small prototype, and asking for help when needed. Emphasise testing and incremental changes.

2. 6

   A bug is reported in production where users cannot add items to their cart during a sale. How do you debug and resolve it?

   Outline checking logs, reproducing the issue, isolating the cause (e.g., database locks, API failure), rolling back if needed, and communicating with the team. Mention post-mortem and preventive measures.

3. 7

   You need to integrate a third-party payment gateway into the checkout flow. What steps would you take?

   Cover reading API docs, handling authentication, error cases, idempotency, security (PCI compliance), and testing with sandbox environments. Mention fallback and retry logic.

4. 8

   How would you handle a situation where your code passes all tests locally but fails in the staging environment?

   Discuss environment differences, configuration management, dependency versions, and logging. Suggest using containerisation or infrastructure as code to reduce drift.

Behavioural and HR

1. 9

   Tell me about a time you worked in a team to complete a project under a tight deadline.

   Use the STAR method. Highlight your specific contribution, how you prioritised tasks, communicated blockers, and the final outcome.

2. 10

   Why do you want to work at a high-growth startup like Nykaa instead of a large MNC?

   Show understanding of startup culture: fast pace, ownership, learning opportunities, and direct impact. Align it with your career goals and willingness to adapt.

3. 11

   Describe a situation where you received critical feedback on your code. How did you respond?

   Demonstrate openness to feedback, a growth mindset, and how you improved. Avoid being defensive; focus on the action you took and the result.

4. 12

   Where do you see yourself in the next three years in terms of technical and career growth?

   Be realistic and ambitious. Mention deepening technical skills, taking ownership of modules, and contributing to architecture or mentoring juniors. Tie it to the company's growth.

Problem Solving and Coding

1. 13

   Given an array of product prices, find two products whose prices sum up to a target amount. How would you optimise it?

   Start with a brute-force O(n^2) approach, then explain using a hash map for O(n) time. Discuss edge cases like duplicate prices and no solution.

2. 14

   How would you detect a cycle in a linked list, and why is it relevant in real-world applications?

   Explain Floyd's cycle detection algorithm. Relate it to detecting infinite loops in workflows or dependency cycles in microservices.

3. 15

   Write a function to reverse a string without using built-in reverse methods. What is the time and space complexity?

   Show a two-pointer or iterative approach. Discuss O(n) time and O(1) space if done in-place. Mention edge cases like empty string or Unicode characters.

4. 16

   How would you find the top K frequently occurring items in a large stream of user clicks?

   Discuss using a hash map with a min-heap or bucket sort. For large streams, mention approximate algorithms like Count-Min Sketch or reservoir sampling.