Coding & Algorithms Interview Questions
Practice 3,429 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 two string algorithm tasks
Solve two string algorithm tasks Answer both parts. A) Parentheses correction: Given a string s consisting only of '(' and ')', output the minimum num...
Implement uniform sampling in squares
Implement uniform sampling in squares Implement a class Square representing an axis-aligned square on the 2D plane that supports sampling a uniformly ...
Reconstruct a tree from two traversals
Reconstruct a tree from two traversals Given two arrays representing the preorder and inorder traversals of a binary tree with unique values, reconstr...
Group employees by shared interests
Given N employees, each with an integer id and a set of interests (strings), write an algorithm to find all employees who share at least one common in...
Check if two-group seating is possible
Check if two-group seating is possible Given an undirected graph represented as an adjacency list where adj[i] lists the indices of guests who know gu...
Compute average customer waiting time
Compute average customer waiting time You are given n customer orders; each order i = [a_i, p_i] where a_i is the arrival time and p_i is the preparat...
Debug and refactor a legacy module
Given a legacy module named DasherPicker and a failing test suite, systematically debug and refactor the code while following a provided review checkl...
Evaluate arithmetic expression without parentheses
Evaluate arithmetic expression without parentheses Write evaluate(s: string) to compute the value of an arithmetic expression containing non-negative ...
Implement weighted random index picker
Implement weighted random index picker Design a class WeightedPicker that is initialized with an array of positive integer weights w and supports pick...
Design 2D DP on a DAG
Design 2D DP on a DAG Given a directed acyclic graph G(V, E) with N nodes, M edges, a designated source s, and an integer L, design a 2D dynamic progr...
Implement DelayQueue with Idempotent Task Execution
Scenario Message broker offers DelayQueue where tasks execute at future timestamps, ensuring idempotency on duplicate IDs. Question Implement a delay ...
Implement LRUCache with O(1) Operations and Thread Safety
Scenario High-traffic API needs constant-time eviction cache. Question Implement an LRUCache supporting get(key) and put(key,val) in O( 1). Describe ...
Develop Auto-Complete System for Dish Suggestions
Scenario Search-as-you-type needs dish suggestions with popularity scores. Question Build an auto-complete system using the given (string, score) tupl...
Decode and Explain Ambiguity in Compression Strings
Scenario Compression library that encodes an array as count-value pairs where value is one digit but count may be many digits. Question Implement deco...
Maximize Non-Overlapping Task Scheduling Efficiency
Scenario Job scheduler on a single machine wants to maximise throughput. Question Given tasks with [start, end) times, return the maximum number of no...
How to Design a Proportional Randomized Sampler?
Scenario Randomized promotion engine must pick an item proportional to its score, but scores have no upper bound. Question Design a sampler pick() tha...
Implement Sampling and Minimize Loss in Numerical Coding
Scenario Numerical coding challenges on sampling and loss minimization. Question a) Implement functions to sample from truncated normal distributions ...
Normalize Columns in Binomial Matrix Efficiently
Scenario Write code that creates a 100×100 matrix of Binomial(1, 0. 5) samples and normalizes each column so it sums to 1. Question Provide an efficie...
Automate Python Virtual Environment Setup on Linux Terminal
Scenario Shell script that automates Python virtual-environment setup on a Linux terminal during a tech interview Question Walk through the script lin...
Solve Python Challenges: Reverse String, Palindrome, Fibonacci, Unique List
Scenario Live coding round – four quick Python exercises Question Implement a function that reverses a string in-place. Write code that returns True i...