Coding & Algorithms Interview Questions
Practice 2,960 real Coding & Algorithms interview questions for 2026. Coding & Algorithms interview questions for top tech firms like Meta, Amazon, Google, Uber, and TikTok — real questions from actual interviews with detailed solutions — to power your interview preparation. This collection is sharply focused on algorithmic patterns (arrays, strings, sliding windows, trees/graphs, dynamic programming, greedy, two-pointers, and hashing), clean, review-ready code, and the explanation skills that distinguish hires. In 2026 expect familiar medium-to-hard problems plus newer twists: AI-enabled or multi-file coding rounds at some companies, more emphasis on explainability and edge-case reasoning, and occasional real-world performance constraints (streaming, concurrency, memory limits). Interviewers evaluate problem framing, algorithm choice, complexity trade-offs, test-case thinking, and communication under time pressure. Best prep mixes pattern-based practice, timed mock interviews, code-review style polishing, and rehearsed explanations of complexity and tradeoffs. Focus your last-mile prep on writing correct, readable code quickly and on explaining why your solution is robust and efficient for production scenarios.
"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."
Find k-th recipient in command propagation order
Chain of Command (k-th Receiver in DFS-by-Child-Id Order) A company org chart forms a rooted tree with n people (nodes), labeled 1..n. You are given a...
Choose K pickup locations minimizing L1 distance
Coding: K Shuttle Pickup Locations (L1) You are given the coordinates of N people on a 2D grid. You want to open K shuttle pickup locations (pickup po...
Select words to maximize unique characters
Problem You are given an array of strings words. You may choose any subset of these strings and concatenate the chosen strings in any order. Your goal...
Implement encryption and constant-time random set
You are asked about two coding topics from an onsite interview: 1. Key-based string encryption Briefly explain the idea of shared-secret encryption...
Generate uniform 0–6 from biased coin
You are given a function: - int getRandom01Biased() returns 0 with probability p and 1 with probability 1-p, where p is unknown and may be any value i...
Return nodes on a tree diameter path
Problem You are given an undirected tree with n nodes labeled 0..n-1 (connected, no cycles). The diameter of a tree is the longest simple path between...
Implement TTL Cache and Tree Balance Reporting
Complete both coding tasks. Task A: Time-limited cache Design and implement an in-memory cache where every key expires after a time-to-live duration. ...
Implement an In-Memory File Storage System
Implement an in-memory file storage service. You need to support files identified by a unique full path string, such as "/docs/a.txt". Each file has a...
Can You Place N Objects?
You are given a binary array slots representing a row of locations. 1 means the location is already occupied, and 0 means it is empty. You want to pla...
Build a Flexible Expense Rules Engine
You are building a rules engine for a corporate credit card product. Employees use company cards for business expenses, and managers define policies t...
Find target-heavy sliding windows
Given an integer array nums, an integer target, and a fixed window size k, solve the following two tasks: 1. Return all contiguous subarrays of length...
Split Markdown Into Header-Aware Chunks
Implement a function that splits a Markdown document into ordered chunks, where each chunk must not exceed a given size limit. A Markdown header is a ...
Implement a versioned recipe management system
You are asked to implement an in-memory Recipe Management System (similar in difficulty to a simple banking/in-memory DB exercise). The system support...
Settle debts with minimal transactions
Question You are given a list of debts among a set of people, expressed as triples (debtor, creditor, amount) (equivalently (payer, payee, amount)), w...
Implement Text Layout and Query Parsing
This interview note described two coding tasks. 1. Format multiple articles into lines Write a function that takes: - articles: a list of articl...
Validate whether brackets are properly nested
Problem: Validate a bracket sequence Given a string s consisting only of the characters '(', ')', '{', '}', '[', ']', determine whether the string is ...
Compute array products excluding self and top-k
Algorithms 1) Product of array except self (no division) Given an integer array nums of length n, return an array ans where: - ans[i] = product of all...
Implement Batched Undo/Redo Layer
You are implementing a simplified document layer for a design tool. The layer stores properties as a map<string, string>. Implement a class that suppo...
Match people to questions using tags and priorities
You are building a simplified “Q&A matching” feature. You have: - people: N people, where person i has a set of expertise tags P[i]. - questions: M qu...
Find motion intervals above threshold
You are processing data from a single security camera. You are given: - A threshold value T (a real number). - A vector (array) of time-stamped motion...