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."
Format Words into Fixed-Width Lines
Given an array of words and an integer maxWidth, arrange the words into lines so that each line has exactly maxWidth characters. Rules: 1. Put words i...
Implement an asyncio-based chat server
Async Chat Server (Python asyncio) Implement a TCP chat server using Python asyncio. Part 1 — Single global room Your server listens on a given port a...
Compute variance of a list in Python
Task Given a Python list of numbers (ints/floats), write code to compute its variance. Requirements - Input: nums: list[float] (length \(n\ge 1\)) - C...
Solve Refueling and JSON Parsing Tasks
Solve the following two independent coding tasks. Task 1: Minimize refueling stops You are driving from position 0 to a destination at distance target...
Solve friend recommendations and time-versioned maps
Solve the following two coding problems. Problem 1: Friend recommendation from weighted likes You are given a directed weighted graph of users. Each r...
Solve tree and DP problems
This coding round contained two algorithm questions: 1. Deepest shared ancestor in a binary tree You are given the root of a binary tree and two ...
Compute longest common subsequence length
Problem You are given two strings s and t. A subsequence of a string is obtained by deleting zero or more characters without changing the order of the...
Find largest group of two-digit numbers sharing digits
You are given an integer array A of length n (1 <= n <= 100). Each element is a two-digit number (e.g., from 10 to 99). Two numbers are considered con...
Count same-color squares in a character grid
You are given a 2D grid (matrix) of characters. Each character represents a color: cells with the same character are considered the same color. Formal...
Add Two Forward-Order Lists
Implement a function that adds two non-negative integers represented by singly linked lists. - Each node stores a single digit. - The digits are store...
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...
Assign tennis bookings to minimum courts
Expanding Tennis Club (Interval Scheduling) You run a tennis club with an unlimited number of courts. Each booking has a start and finish time. `text ...
Implement round-robin load balancer
Implement a load balancer that distributes incoming requests across N backend servers in strict round-robin order. Requirements: ( 1) Support addServe...
Solve coding and AI-assisted tasks
This interview included several algorithm problems across a phone screen, onsite coding, and an AI-assisted coding round. Solve the following tasks: 1...
Solve two interview coding problems
The interview included two coding problems. Problem 1: Find valid robot locations in a grid You are given a 2D grid containing empty cells and obstacl...
Infer an Unknown Alphabet Order
You are given a list of words that is already sorted according to an unknown alphabet. Derive one valid ordering of the characters in that alphabet. R...
Implement Python feature and resolver metaprogramming
You are given a skeleton for a small Python "feature" framework. The goal is to use metaprogramming to: 1. Parse type-annotated classes into Feature o...
Design Composable Event Recommendations
Build a flexible event recommendation engine for a ticket marketplace. You are given these domain objects and services: - Event(id, name, city, date) ...
Solve theatre seating and ticker extraction
Implement the following two coding tasks. 1. Allocate groups in a movie theater You are given an integer n representing the number of rows in a movie ...
Find longest common ordered restaurant list
You have two delivery drivers who each have a pickup plan represented as a list of restaurant IDs (strings). Because there is only one car, the combin...