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."
Compute longest rising path in a grid
Given an m×n grid of integers, find the length of the longest path where each step moves up, down, left, or right to a strictly larger value. Return t...
Find all pairs summing to target in sorted array
Given a non-decreasing array of integers nums and an integer target, return all unique pairs of indices (i, j) with i < j such that nums[i] + nums[j] ...
Sort characters by frequency
Given an ASCII string s, reorder its characters in decreasing order of frequency. If multiple characters share the same frequency, break ties by ascen...
Segment a message with width-constrained suffixes
Given a message string s and an integer width W, split s into consecutive segments and append a suffix "i/n" to each segment indicating its 1-indexed ...
Design LCA and find K closest points
Part A — LCA with parent pointers: You are given two nodes a and b in a rooted tree where each node has a parent pointer (you may or may not have dire...
Compute delivery times on a grid
You are given a 2D grid with cells marked as 'M' (warehouses), 'C' (customers), 'X' (obstacles), and '.' (roads). You can move up, down, left, or righ...
Minimize steps to reduce integer
Given a positive integer n (1 <= n <= 2^61 - 1), in one step you may replace n with n/2 if n is even, or with n+1 or n-1 if n is odd. Return the minim...
Solve four algorithmic problems
Answer the following independent algorithmic questions: 1) Count extendable prefixes for '10' subsequences: Given a binary string s and an integer k, ...
Implement Python LRU cache with varargs
Implement an LRU cache in Python as a decorator cache(maxsize) that memoizes a target function's results. Must support positional args, args, and *kwa...
Simulate robot path and detect boundedness
A robot starts at (0, 0) facing north on an infinite 2D plane. It executes a command string s consisting of 'G' (move forward one unit), 'L' (turn lef...
Count regions with DFS
Given an m x n grid of 0s and 1s, count the number of connected regions consisting of 1s using depth-first search (4-directional adjacency). Return th...
Serialize and deserialize a dictionary trie
Question Design and implement serialization and deserialization for a trie (prefix tree) that stores a large dictionary of lowercase English words. Th...
Implement binary search lower/upper bounds
Question Given a non-decreasing sorted integer array nums of length n and a target value, implement two functions using binary search: 1. lower_bound(...
Compute left and right views once
Given the root of a binary search tree, output two lists: the nodes visible from the left side and the nodes visible from the right side, from top to ...
Reverse between equal-value nodes in list
Given the head of a singly linked list and a target value v, locate the first two nodes whose values equal v (call them A and B, with A before B) and ...
Count subarrays equal to target
Given an integer array nums and an integer k, return the number of contiguous subarrays whose sum equals k. Provide an algorithm better than O(n^ 2), ...
Design a transactional in-memory key–value store
Implement an in-memory key–value store that supports transactions. The system must process these commands: ( 1) SET key value — assign or overwrite a ...
Maximize profit with transaction fees
You are given an array prices where prices[i] is the price of a stock on day i and an integer fee representing the commission charged when you sell. Y...
Implement top-K over a stream
Given a high-volume stream of events (e.g., account IDs from new account openings), design and implement a data structure that supports: ( 1) insertin...
Implement 2D transforms and find max-lit point
Part A — 2D array transforms: Given an m×n integer matrix, implement the following in-place operations with clear function boundaries and complexity: ...