Coding & Algorithms Interview Questions
Practice 3,469 real Coding & Algorithms interview questions for 2026. Covers companies like Meta, Amazon, Google, Uber, and Microsoft. Real questions from actual interviews with detailed solutions — ideal for focused interview preparation. Coding & Algorithms interview questions are the single most common technical gate for software engineering roles and are used to evaluate problem framing, algorithm selection, complexity trade-offs, correctness, edge-case reasoning, and clear communication under time pressure. Expect this category to appear in early technical screens and repeatedly across onsite loops at companies that weight it heavily (notably Meta, Google, and Amazon). Interviews will test arrays and strings, trees and graphs, dynamic programming, hashing and two‑pointer techniques, and the candidate’s ability to test and optimize code in a shared editor. Prepare with timed mock interviews, practice in the same editor you’ll use live, and build a progressive schedule that moves from fundamentals to medium/hard problems; typical candidates invest several weeks to a few months of focused practice depending on seniority and target company.
"I got asked a hardcore MCM DP question and I saw it on PracHub as well. Solved that question in 5 minutes. Without PracHub I doubt I could solve it in 5 hours. Though somehow didn't get hired, perhaps I guess I solved it too fast? /s"
"Believe me i'm a student here jn US. Recently interviewed for MSFT. They asked me exact question from PracHub. I saw it the night before and ignored it cause why waste time on random sites. I legit wanna go back and redo this whole thing if I had chance. Not saying will work for everyone but there is certainly some merit to that website. And i'm gonna use it in future prep from now on like lc tagged"
"10 years of experience but never worked at a top company. PracHub's senior-level questions helped me break into FAANG at 35. Age is just a number."
"I was skeptical about the 'real questions' claim, so I put it to the test. I searched for the exact question I got grilled on at my last Meta onsite... and it was right there. Word for word."
"Got a Google recruiter call on Monday, interview on Friday. Crammed PracHub for 4 days. Passed every round. This platform is a miracle worker."
"I've used LC, Glassdoor, and random Discords. Nothing comes close to the accuracy here. The questions are actually current — that's what got me. Felt like I had a cheat sheet during the interview."
"The solution quality is insane. It covers approach, edge cases, time complexity, follow-ups. Nothing else comes close."
"Legit the only resource you need. TC went from 180k -> 350k. Just memorize the top 50 for your target company and you're golden."
"PracHub Premium for one month cost me the price of two coffees a week. It landed me a $280K+ starting offer."
"Literally just signed a $600k offer. I only had 2 weeks to prep, so I focused entirely on the company-tagged lists here. If you're targeting L5+, don't overthink it."
"Coaches and bootcamp prep courses cost around $200-300 but PracHub Premium is actually less than a Netflix subscription. And it landed me a $178K offer."
"I honestly don't know how you guys gather so many real interview questions. It's almost scary. I walked into my Amazon loop and recognized 3 out of 4 problems from your database."
"Discovered PracHub 10 days before my interview. By day 5, I stopped being nervous. By interview day, I was actually excited to show what I knew."
"I recently cleared Uber interviews (strong hire in the design round) and all the questions were present in prachub."
"The search is what sold me. I typed in a really niche DP problem I got asked last year and it actually came up, full breakdown and everything. These guys are clearly updating it constantly."
Solve Array Merge and Parentheses Cleanup
You are asked to solve two coding problems. Problem 1: Merge Three Sorted Arrays Given three integer arrays, each sorted in nondecreasing order, merge...
Implement Tail and Find Monster Cost
This entry contains two coding tasks from the same interview category. Task A: Implement a file tail operation Implement a function tail(filePath, n) ...
Implement an In-Memory Database
Design and implement an in-memory database that stores records by key. Each record is a map from field to integer value. Implement the following funct...
Solve Decimal Coin Change
Given a list of coin denominations represented as decimal values and a target amount represented as a decimal value, return the minimum number of coin...
Implement Sorted Search and Array Updates
Implement the following independent array functions. Part 1: Search a sorted array Given a sorted array of integers nums in nondecreasing order and an...
Find Earliest Full Connectivity Timestamp
You are given: - A list of all user IDs in a ride-sharing system. - A chronological text log of ride-sharing events. Each relevant event contains a ti...
Implement Cache, Undo, and DFS
This question evaluates implementation skills in data structures, algorithmic complexity, and state-management patterns by combining a timed in-memory...
Solve Quickselect, Tree Distance, and Prefix Substrings
You are given three independent coding tasks. 1. Implement Quickselect - Given an unsorted integer array nums and an integer k, return the k-th sma...
Build a Streaming Chat Input
Implement a minimal front-end chat interface, similar to a stripped-down AI assistant (think a bare-bones ChatGPT). The user types a prompt, submits i...
Solve Tree View and Triplet Sum
You are asked to solve two coding problems. Problem 1: Return the nodes visible from the right Given the root of a binary tree, return the values of t...
Implement Grid Spread and Transactional Store
You have two coding tasks. Task A: Compute Contamination Spread Time Given an m x n grid: - 0 means an empty cell. - 1 means a fresh item. - 2 means a...
Implement Integer Square Root
Given a non-negative integer x, implement sqrt(x) and return the integer part of its square root, i.e., floor(sqrt(x)). Requirements: - Do not use a b...
Count Good Subsequences With Equal Character Frequencies
A subsequence is formed by deleting zero or more characters from a string without changing the order of the remaining characters. A non-empty subseque...
Solve Watcher Simulation And Integer Conversion
You are asked to solve two independent coding tasks. Task 1: Count players that reach the finish There is a one-dimensional track with integer positio...
Find the First Unique IP
You are processing a chronological stream of server hit records. Each record contains an IP address as a string. Design and implement a component that...
Implement Streaming Word Counter
Implement a class that records word frequencies from a stream of text. The class should support the following operations: 1. add_text(text: str) -> No...
Implement a Resizable Deque
Implement a double-ended queue (deque) data structure backed by a circular array. Your deque should support insertion and removal from both ends and s...
Flatten a Nested Integer List
Flatten a Nested Integer List A nested list contains either integers or other nested lists, to arbitrary depth. Return all integers in left-to-right o...
Solve a Two-by-Three Sliding Puzzle
Solve a Two-by-Three Sliding Puzzle You are given a 2 x 3 board containing the integers 0 through 5 exactly once. The value 0 is the empty square. In ...
Count Consecutive Positive Integer Sums
Count Consecutive Positive Integer Sums Given a positive integer n, return the number of ways to write n as a sum of one or more consecutive positive ...