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."
Select next Hangman letter
Given the current state of a Hangman game, implement a function that selects the next letter with the highest likelihood of appearing in the secret wo...
Compute exclusive times and call stack from logs
Design an algorithm that, given a single-threaded program's execution log, computes per-function exclusive durations and reconstructs the active call ...
Implement Union-Find and track components
Implement a Disjoint Set Union (Union-Find) data structure with union by rank and path compression. Design the API to support union(a, b), connected(a...
Design a music player with favorites cap
Implement an in-memory music player that supports: addSong(id, metadata), removeSong(id), play(id), pause(), next(), prev(), getNowPlaying(), queueSon...
Implement valid 1-D convolution with bias
Question Implement a "valid" 1-D convolution function in the cross-correlation sense. Given an input array of numbers, a kernel (filter) array of numb...
Compute waits and find distance-k node pairs
Part 1 — Array next-higher wait: Given an integer array A where A[i] is the measurement for day i (0-indexed), return an array W of the same length su...
Implement a min-heap column allocator
You are given an integer k (number of columns) and an array posts of positive integers where posts[i] is the height of the i-th post. All columns star...
Design card deck with shuffle and order
Design a playing-card deck library with two methods: shuffle() to return a uniformly random permutation of a standard 52-card deck, and order() to ret...
Design LRU cache with O(1) operations
Design and implement an in-memory cache that evicts the least recently used entry when capacity is reached. Support get(key) and put(key, value) in O(...
Design an O(1) recency-evicting cache
Design and implement a fixed-capacity in-memory cache that supports get(key) and put(key, value) in average O( 1) time. When capacity is exceeded, evi...
Design high-throughput hashing for kernels
Design a high-throughput hash-based lookup to be called inside a tight kernel. Choose between open addressing and chaining, specify the load factor, p...
Validate alternating checkout/return logs
Given a chronological list of events logs of the form (timestamp, book_id, is_checkout) where is_checkout is True for a checkout and False for a retur...
Implement snake game and find org LCA
Part A — Snake Game Engine: Implement a grid-based snake game. The board has height H and width W (0-indexed, row-major). The snake starts at (0, 0) m...
Implement file deduplication at scale
Implement a command-line tool to find duplicate files in a directory tree. Use OS/pathlib primitives to recursively enumerate files. Apply prefilters ...
Design a coupon pricing engine
Design and implement a coupon application engine for a shopping cart. Each Item has id, category, and unitPrice. A Coupon has: applicableCategories (o...
Find kth smallest in sorted matrix
Given an n x n matrix where each row and each column is sorted in nondecreasing order, and an integer k (1 ≤ k ≤ n^ 2), return the k-th smallest eleme...
Compute binary tree left-side view
Given a binary tree, return the values visible from the left side when looking from top to bottom. If multiple nodes exist at the same depth, the left...
Implement 2D word search variants and analyze complexity
Given an m x n grid of uppercase letters board and a string word, implement two related functions: ( 1) Fixed-direction search: Return true if word ap...
Implement BFS shortest path in grid
Implement a function that returns the length of the shortest path in an unweighted 2D grid from the top-left cell (0, 0) to the bottom-right cell (m-1...
Generate boolean truth table
Implement a function that, given a string boolean expression, outputs a complete truth table. The expression syntax is: variables are single uppercase...