Expedia India Software Engineer Interview: Rounds, Questions and Preparation

What the job involves

Software Engineers at global tech companies like Expedia India build and maintain scalable web and mobile applications that serve millions of travelers. Day to day, they write clean code, collaborate with cross-functional teams, and solve problems related to search, booking, payments, and personalization. Freshers typically start with well-defined tasks and gradually take ownership of features.

Role and Technical Knowledge

1. 1

   Explain the difference between an array and a linked list. When would you use one over the other in a travel booking system?

   Cover memory layout, access time, insertion/deletion costs, and give a scenario like storing search results versus a queue of booking requests.

2. 2

   What is a REST API? How would you design an endpoint to fetch hotel details by city?

   Mention HTTP methods, status codes, resource naming, and query parameters. Example: GET /hotels?city=paris.

3. 3

   Explain the concept of database normalization. Why is it important for a booking platform?

   Discuss reducing redundancy, ensuring data integrity, and how it helps avoid anomalies in user, booking, and payment tables.

4. 4

   What is the time complexity of binary search? Describe a scenario where you would use it in a flight search feature.

   State O(log n), mention sorted data, and give an example like searching for available flights by departure time.

Practical Scenarios

1. 5

   You are asked to optimize a slow API that returns hotel search results. What steps would you take?

   Suggest profiling, adding indexes, caching frequent queries, pagination, and reducing payload size.

2. 6

   A bug is reported where users sometimes see incorrect prices during checkout. How would you debug it?

   Talk about reproducing the issue, checking logs, reviewing recent changes, and writing unit tests for price calculation logic.

3. 7

   You need to integrate a third-party payment gateway. What factors would you consider?

   Cover security, error handling, idempotency, retry logic, and compliance with PCI standards.

4. 8

   How would you design a simple URL shortener for sharing travel itineraries?

   Discuss hashing, database schema, collision handling, and redirection service.

Behavioural and HR

1. 9

   Tell me about a time you worked in a team to complete a project. What was your role?

   Use STAR method: describe situation, task, action, and result. Highlight collaboration and your specific contribution.

2. 10

   Describe a challenging technical problem you faced and how you solved it.

   Show problem-solving process, research, and persistence. Mention what you learned.

3. 11

   Why do you want to work as a Software Engineer in the travel tech industry?

   Connect personal interest in travel with technical challenges like scale, real-time data, and user impact.

4. 12

   Where do you see yourself in five years?

   Express growth in technical skills, taking ownership, and contributing to larger projects. Align with company's career path.

Problem Solving and Coding

1. 13

   Given a list of flight prices, find two flights whose prices sum to a given budget.

   Use a hash map for O(n) solution. Explain trade-offs with sorting and two-pointer approach.

2. 14

   Write a function to check if a string is a palindrome, ignoring spaces and case.

   Discuss two-pointer technique, string manipulation, and edge cases like empty string.

3. 15

   How would you find the first non-repeating character in a string?

   Use a frequency array or hash map. Mention O(n) time and O(1) space for fixed character set.

4. 16

   Explain how you would reverse a linked list iteratively and recursively.

   Cover pointer manipulation for iterative, and base case plus recursion for recursive. Mention time and space complexity.