Schlumberger

Role: Software Developer

College: Not Specified

Interview Date: 2025-07-12

Interview Type: Not Specified

Result: Not Specified

Difficulty: Medium

Rounds: 4 rounds

Topics Asked: Data Structures (Arrays, Trees, Binary Search Tree, Binary Tree Traversals), Algorithms (XOR solution, Hashing), OOPS concepts, General Technical Awareness, HR questions

Experience:

The candidate first qualified an online coding test with two coding questions and six multiple-choice questions.

Round 1 (Technical - Data Structures & Algorithms): The interviewer was friendly. The first coding question was: "Given a list of array elements with all unique elements, except one element which comes two times, find that duplicate number." The candidate initially gave a hashing solution but the interviewer asked for an O(1) space complexity and O(n) time complexity solution. The second question was: "In an array, all elements are repeated twice except one element which comes thrice, find that element." The candidate provided a simple XOR solution. The discussion then moved to trees, covering binary trees, BST, complete binary trees, and traversals (inorder, preorder, postorder, level order). The candidate was asked to code for inserting elements in a Binary Search Tree, level order traversal, and finally zig-zag traversal.

Round 2 (Technical - OOPS): This round focused on the candidate's understanding of OOPS concepts. The interviewer presented scenarios and asked the candidate to design classes and methods on a whiteboard based on their understanding of the problem.

Round 3 (TCM Round - Technical Competency Management): This round assessed the candidate's tech awareness and their preferred language or technology to work with.

Round 4 (HR Round): Standard HR questions were asked, including strengths and weaknesses, personal attributes, salary expectations, and "why Schlumberger?".

Overall Experience: The candidate felt that if one has practiced "Must Do Coding Questions" on GeeksforGeeks, technical interviews wouldn't be a problem.