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."
Find the Smallest String After One Decrement
You are given a string s consisting only of lowercase English letters. You must perform exactly one operation: 1. Choose one non-empty contiguous subs...
Minimize the Maximum Edge on a Path
Minimize the Maximum Edge on a Path You are given a weighted undirected graph and two vertices, start and target. Define the stress of a path as the l...
Implement a Hierarchical File System
Implement an in-memory hierarchical file system. Create a class FileSystem with the following methods: - FileSystem() initializes an empty file system...
Support Dynamic Range Sums
Implement a data structure over an integer array nums. Part 1: If the array never changes, support sumRange(left, right) that returns the sum of eleme...
Validate abbreviations and brackets
The coding round included two short implementation problems: 1. Abbreviation validation Given a lowercase word word and a string abbr, determine wheth...
Sort trade executions into a canonical order
You are building a small component in a trading system that consumes trade execution records from an upstream feed. The records may arrive out of orde...
Write Transaction Analytics SQL Queries
You are given a credit-card transaction dataset with the following tables. transactions | column | type | description | |---|---|---| | transaction_id...
Implement a Formula Spreadsheet
Design and implement a small in-memory spreadsheet. The spreadsheet must support cell labels such as A1 and B10, where a label consists of uppercase l...
Implement Due Broadcast Sender
You are building a notification system. You are given: - A mapping from company_id to a list of subscriber IDs. - A list of broadcast logs. Each log c...
Count Blocked Rate-Limited Requests
You are given an in-memory request log for a web platform. Each log entry has: - timestamp: an ISO-8601 UTC timestamp - request_ip: the client IPv4 ad...
Build a simplified Wordle game in React
This question evaluates a candidate's competency in React-based front-end development, covering component design, state management, asynchronous HTTP ...
Implement Interval Insert and Dedup
This question evaluates skills in array and interval data-structure manipulation, in-place modification under space constraints, and general algorithm...
Implement a Spreadsheet With Formulas
This question evaluates understanding of data structures and algorithms for dependency management, expression parsing and evaluation, and detection of...
Write pseudocode for a ReAct-style loop
Coding prompt (pseudocode) Write pseudocode (does not need to compile) for a ReAct-style agent loop that alternates between reasoning and actions. Req...
Parse and Reconstruct Stack Trace
Given a multi-line stack trace string from a single thread (e.g., each frame is in the form 'at Module::Function(file:line)'), design and implement a ...
Explain data structure fundamentals
Explain how a hash map works internally: hashing, collision resolution strategies (separate chaining vs. open addressing), load factor, and resizing. ...
Find top-k frequent elements efficiently
Given an array (or stream) of integers and an integer k, return any ordering of the k most frequent values. Implement a solution using a heap and disc...
Solve word segmentation and React palindrome validation
Part A — String segmentation: Given a non-empty string s and a dictionary of valid words, design an algorithm to determine whether s can be segmented ...
Optimize switching puzzle solution
Consider a switching puzzle on an m×n grid of lights where toggling a cell flips its state and that of its orthogonal neighbors (Lights Out variant). ...
Compare two programs for equivalence
You are given two short programs (or functions) that process an integer array A (|A| ≤ 10^ 5). Determine whether they are functionally equivalent for ...