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."
Count Substrings with No Repeated Characters
Count Substrings with No Repeated Characters Given a lowercase English string s, return the number of nonempty contiguous substrings whose characters ...
Build Quadtree and Find Grid Words
This question evaluates divide-and-conquer tree construction and recursive spatial data structures for the quadtree task, and grid-based search and ba...
Write SQL for basic user metrics
You are given a simplified schema for a fictional social app called Nextagram: - users(user_id PK, username, created_at TIMESTAMP) - follows(follower_...
Implement four coding challenges
You are asked to solve the following four independent coding problems. --- 1) Block Placement Simulator (Tetris-like) You have an empty n x m grid (ro...
Compute Minimum Task Completion Time
This question evaluates understanding of graph algorithms (topological sort and DFS), dependency scheduling, cycle detection, and critical-path comput...
Implement stream random sampling in Python
You are given an unbounded stream of items that cannot be stored entirely in memory. Write Python code to maintain a uniform random sample from the st...
In-Memory File System: Create, Track Duplicates, and List
This question evaluates a software engineer's ability to design and implement an in-memory file system, testing data structure selection, path parsing...
Implement a simplified grep with extensible flags
Problem Implement a simplified version of grep that searches a text file and returns the lines that match a given query string. You should focus on cl...
Cluster 3D Points by a Distance Threshold
Implement cluster_points_3d(points, D). Create an undirected edge between two distinct 3D points when their Euclidean distance is strictly less than D...
Find Largest Adjacent Stock Price Change
This question evaluates algorithmic problem-solving and data-manipulation skills, specifically date-based sorting, computing signed versus absolute ad...
Solve interval merging and histogram area
The coding round included two algorithm problems: 1. Merge overlapping intervals: Given a list of closed intervals [[start1, end1], [start2, end2], .....
Fix the Broken Search Filter in a Book Catalog API
This question tests a backend engineer's ability to implement correct filtering logic, including case-insensitive substring matching, whitespace trimm...
Implement a multi-level digital recipe manager
Implement a RecipeManager class for a digital recipe manager. The task is progressive (Levels 1–4). You can assume a single-process in-memory implemen...
Find Minimum Rooms Needed
This question evaluates understanding of interval scheduling and conflict detection in time ranges, along with algorithmic reasoning and appropriate d...
Implement a Cursor-Based Text Editor
This question evaluates understanding of data structures and algorithmic efficiency for mutable sequences and cursor manipulation, including analysis ...
Choose optimal guesses for green-only Wordle
This question evaluates probabilistic reasoning, expected-value optimization, information partitioning, and algorithmic efficiency in selecting guesse...
How do you sample uniformly from an infinite stream?
This question evaluates understanding of streaming algorithms, randomized sampling and probability, and algorithmic space–time trade-offs involved in ...
Solve binary-tree reverse printing and LPS
You are given a binary tree node definition: - TreeNode { int val; TreeNode left; TreeNode right; } Answer the following two algorithmic questions. 1)...
Count Distinct Values in a Sorted Array When K Is Small
Count Distinct Values in a Sorted Array When K Is Small Given an integer array sorted in nondecreasing order, return the number of distinct values. Le...
Resolve a cd Path Against the Current Directory
Resolve a cd Path Against the Current Directory Implement path resolution for a simplified Unix-like cd command. cwd is a normalized absolute path. ar...