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."
Implement image carousel with comments and upvotes
Implement an image carousel that supports: 1) cycling forward/backward and autoplay with a configurable interval; 2) a per-image comment thread with c...
Check Root-To-Leaf Target Sums In A Binary Tree
You are given the root of a binary tree and an integer target. Each node contains an integer value. Return true if there is at least one path from the...
Detect Currency Arbitrage After a Cycle Fee
Detect Currency Arbitrage After a Cycle Fee You are given a matrix of positive currency exchange rates, where rates[i][j] units of currency j are rece...
Count Bounded Buy-and-Sell Sequences
Count Bounded Buy-and-Sell Sequences You start with k shares. On each transaction day, you either buy one share or sell one share, but holdings may ne...
Order Classes by Prerequisites with Recursive DFS
Order Classes by Prerequisites with Recursive DFS Implement class_order(classes, prerequisites) using recursive depth-first search. classes contains d...
Schedule Incremental Labeling Tasks
This question evaluates skills in designing stateful incremental schedulers, fairness and load-balancing algorithms, deterministic tie-breaking, and e...
Find minimal time for four people crossing
Assume there are four people who need to cross a narrow bridge at night using a single flashlight. - Each person \(i\) requires a different, known amo...
Design paint editor with undo/redo
Implement a simplified Paint editor that supports drawing on a 2D canvas and reverting changes using undo and redo operations. Canvas You are given a ...
Convert Samples into Event Intervals
This question evaluates understanding of array and sequence processing, run-length encoding concepts, and interval representation for time-ordered tra...
Implement a Referral Network
This question evaluates skills in modeling and manipulating directed acyclic graphs, implementing graph-based ranking metrics (reachability and flow c...
Find Unique Target-Sum Pairs
This question evaluates array-processing skills, correctness in handling duplicate values, and the ability to identify unique value pairs whose sums m...
Implement an In-Memory File System
This question evaluates understanding of file-system abstractions, tree-based data structures, path parsing, and stateful directory and file managemen...
Find Maximum Eastbound City Visits and Parse CSV
The first problem evaluates algorithmic reasoning about ordering constraints and subsequence selection, testing skills in sequence algorithms, multidi...
Implement custom iterators and interfaces
Implement custom iterators and interfaces Define a minimal Iterator interface (e.g., hasNext(), next()) for integers without using IDE-generated scaff...
Generate Weighted Random Keys With Add And Remove
Design a class that stores string keys with positive integer weights. add_key(key, weight) inserts or updates a key. generate() returns one key random...
Build referral chains and detect cycles
You are given a directed referral graph where each user may have at most one referrer. Input file 'referrals.csv' has columns: user_id (INT), referred...
Implement Portfolio Trading Optimizer
You are given an array prices, where prices[i] is the price of one stock on day i. You may perform multiple buy/sell transactions over the period, but...
Find Top Creators and Login Streaks
This question evaluates proficiency in data aggregation, algorithmic optimization for top-k retrieval, and SQL time-series analysis using window funct...
Write SQL for car rental utilization by city
SQL / Data Query Prompt (Car Rental) You are given four tables: user - user_id location - location_id - city car - car_id - car_size (e.g., compact, m...
Check if all substrings are anagrams of words
You are given a string s (letters only) and access to an English dictionary dict (a set of valid words). Return true if every contiguous substring of ...