IBM
Global technology and consulting firm with deep roots in enterprise IT and AI.
3 Rounds
~14 Days
Medium
The Interview Loop
Recruiter Screen (30 min)
Standard fit check, behavioral questions, and resume overview.
Technical Loop (3-4 Rounds)
Deep dive into domain knowledge, coding, and system design.
Interview Question Bank
Backend Engineer
•
Coding
•
easy
Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target.
#Arrays
#Hash Table
Backend Engineer
•
Coding
•
easy
Given a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.
#Strings
#Stack
Backend Engineer
•
Coding
•
medium
Given an array of intervals where intervals[i] = [starti, endi], merge all overlapping intervals.
#Arrays
#Sorting
Backend Engineer
•
Coding
•
medium
Given an m x n 2D binary grid grid which represents a map of '1's (land) and '0's (water), return the number of islands.
#Graph
#DFS
#BFS
Backend Engineer
•
Coding
•
easy
Given the head of a singly linked list, reverse the list, and return the reversed list.
#Linked List
Backend Engineer
•
Coding
•
medium
Given an integer array nums and an integer k, return the k most frequent elements.
#Heap
#Hash Table
#Bucket Sort
Backend Engineer
•
Coding
•
medium
Given a string s, find the length of the longest substring without repeating characters.
#Sliding Window
#Strings
#Hash Table
Backend Engineer
•
Coding
•
easy
Given a string s, find the first non-repeating character in it and return its index. If it does not exist, return -1.
#Strings
#Hash Table
Difficulty Radar
Based on recent AI-sourced data.
Meet Your Interviewers
The "Standard" Interviewer
Senior EngineerFocuses on core competencies, system constraints, and clear communication.
SimulateUnwritten Rules
Think Out Loud
Always explain your thought process before writing code or drawing architecture.