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."
Guide a mouse to find cheese with APIs
This question evaluates the ability to reason about graph exploration and stateful API interaction in an unknown 2D grid, assessing competencies in se...
Rotate a Matrix In Place
Given an n x n matrix of integers, rotate the matrix 90 degrees clockwise. Implement the function in Python. You may use a straightforward approach wi...
Implement three interview-style coding tasks
You are given three separate coding tasks, all focused on algorithm and data-structure design. --- Task 1: Longest Bounded-Difference Subarray You are...
Determine if subarray sums to target
You are given an array of non-negative integers and a non-negative integer target. Determine whether there exists a contiguous subarray (continuous se...
Find path between two nodes in a binary tree
Problem Given a binary tree and two target nodes a and b, return the simple path from a to b (inclusive) as an ordered list of node values. - The path...
Find single element when others repeat k times
You are given a sorted array of integers nums in non-decreasing order, and an integer k ≥ 2. Every value in nums appears exactly k times in a row, exc...
Compute subarray span for each element
You are given an integer array nums of length n. For each index i (0 <= i < n), define ans[i] as the maximum possible length of a contiguous subarray ...
Design an in-memory database with TTL and backups
You are asked to implement a small in-memory “database” that evolves across 4 parts. In each part you may reuse your previous code and only add/extend...
Find longest common ordered restaurant list
You have two delivery drivers who each have a pickup plan represented as a list of restaurant IDs (strings). Because there is only one car, the combin...
Maximize profit from one or many stock trades
You are given an integer array prices where prices[i] is the price of a stock on day i (0-indexed). Answer the following two subproblems: 1. Single tr...
How would you sort filenames with numeric segments?
You are given a list of filename strings (e.g., "file10.txt", "file2.txt", "10file.txt"). Implement a custom sort for these strings using a comparator...
Implement an LRU cache
Design and implement an in-memory cache that evicts entries using the Least Recently Used (LRU) policy. The cache should store key–value pairs and sup...
Determine whether points form squares
Problem: Square detection and counting from point coordinates You are given points on a 2D plane with integer coordinates. Part A — Validate a single ...
Compute servers needed for daily recurring jobs
You operate a cluster of identical servers that run recurring daily jobs. For a single day, you are given a list of job execution intervals. Each inte...
Minimize calls to find all bad test pairs
You have \(n\) atomic tests \(t_1, t_2, \dots, t_n\). You are given access to a black-box function: `python bool runTest(set<Test> S) ` which behaves ...
Find shared objects across two log files
You are given two large log files representing activity on two different days. Each line of each log has three fields: - timestamp: a time value (you ...
Implement a per-user API rate limiter
You are building an API gateway that must enforce per-user rate limits. Task Implement a rate limiter with the following API: - RateLimiter(int maxReq...
Find shortest substring with n unique letters
Problem You are given a string s consisting of lowercase English letters and an integer n (1 ≤ n ≤ 26). Find the length of the shortest contiguous sub...
Process multi-currency payments with fees
This question evaluates a software engineer's competency in precise integer arithmetic and rounding semantics, multi-currency FX conversion with basis...
Find K-th Largest and Longest Vacation
Solve the following two coding problems. 1. Find the k-th largest element Given an integer array nums and an integer k, return the element that wou...