Expedia

Role: SDE-2 (Java Backend)

College: Not Specified

Interview Date: Not Specified

Interview Type: Full-Time

Result: Selected

Difficulty: Medium

Rounds: 5 stages (1 Online Assessment + 4 Interview Rounds)

Topics Asked: Data Structures, Algorithms (Strings, Dynamic Programming, Matrices/2D Arrays, Linked List, LRU Cache, Binary Tree Traversal, SQL), System Design (Scalability, Databases, Caching, Multithreading), Low-Level Design (Invoice generation system), Behavioral (Cultural Fitment, Expedia Group Values)

Experience:

The hiring process for the SDE-2 Java Backend role at Expedia consisted of 5 stages.

1. HackerRank Assessment: This was a 90-minute assessment with 3 questions of difficulty equivalent to LeetCode medium questions. Topics included strings, dynamic programming, and matrices/2D arrays. The candidate was able to code all 3 questions with all test cases passed. After this round, HR contacted the candidate after 15-20 days to schedule interviews, which took over 50 days to be finally scheduled.

2. Technical Interview Round 1 (Coding and DS/Algo): This round was conducted on HackerRank and included 2 questions. The first question was to "Find the longest substring with non-repeating characters," for which the candidate optimized a brute force solution to O(n). The second question was to "Implement LRU Cache," using a HashMap and a LinkedList, which the interviewer found acceptable despite expecting a LinkedHashSet. The interviewer also asked an additional SQL question to find an employee with the 4th highest salary.

3. Technical Interview Round 2 (Coding and DS/Algo): The interviewer initially presented a problem related to finding the pair with the minimum difference from two unsorted arrays, which was similar to a known problem but required returning the pair. The second question was "Zigzag traversal of a binary tree," solved using a stack. The candidate focused on thinking aloud, discussing edge cases, and time/space complexity.

4. Technical Interview Round 3 (System Design and LLD): This round started with a discussion on the candidate's past work and system design choices. The interviewer asked about ensuring scalability, discussing aspects like database choices for microservices, caching, and multithreading. This was followed by an LLD problem to write code for an invoice generation system.

5. Hiring Manager Interview Round: This round focused on past work and behavioral questions, particularly cultural fitment. The recruiter had provided a document with Expedia Group values and expected questions. No technical questions were asked in this round.

Overall, the interview went well, and the candidate received an offer letter within a week of the final interview.