Capital One Software Engineer Interview Questions
Practice the exact questions companies are asking right now.
Solve string merge and grid path tasks
Question Given two equal-length strings s1 and s2, create a new string by iterating i = 0 … n-1, comparing s1[i] with s2[n-1-i]: append s1[i]; if the ...
Implement deposit, withdraw, and transfer in a class
Problem Implement a class AccountService that supports basic money operations on accounts. Operations - deposit(accountId, amount) - withdraw(accountI...
Design a cross-region event processing platform
Scenario Design a cross-region event processing platform that ingests events from producers, stores them durably, and delivers them to multiple consum...
Describe leadership challenges and managing a difficult report
Answer the following behavioral questions with specific examples: 1. In a project you led, what was the most challenging part and why? 2. Tell me abou...
Design a highly reliable account balance system
Scenario You are designing a backend service that stores and updates user account balances (like a wallet/bank ledger). The system must be highly reli...
Apply commands to transform a matrix
You are given an integer matrix A of size n × m and a list of string commands to apply in order. Implement the commands and return the final matrix. C...
Count ordered pairs that concatenate to target
Given a list of integers numbers and an integer target, count the number of ordered pairs (i, j) with i != j such that concatenating numbers[i] follow...
Design a scalable banking system
System Design: Online Banking Platform Context Design an online banking platform (scope similar to a credit-card application system) that supports: - ...
Implement 2D transforms and find max-lit point
Part A — 2D array transforms: Given an m×n integer matrix, implement the following in-place operations with clear function boundaries and complexity: ...
Solve four algorithmic coding tasks
You will solve four independent coding tasks: 1) Count equal-value pairs in an array: Given an integer array nums of length n, return the number of in...
Solve powers, phases, grid pops, and swaps
Solve the following four problems: 1) Count powers of k in an array: Given an array of positive integers nums and an integer k >= 1, return how many e...