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."
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"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."
Implement an IPv4 Range Iterator
This question evaluates implementing iterative data structures and range-handling algorithms alongside numeric representation of IPv4 addresses and bi...
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...
Implement Random Connectivity and Grid Routing
This entry contains two independent coding problems. Problem 1: Uniformly connect node groups You are given k non-empty, disjoint groups of unique nod...
Determine Whether Queries Can Zero Array
This question evaluates understanding of range-based array operations and feasibility under bounded per-index decrements, testing skills in interval r...
Determine Whether Queries Can Zero Array
This question evaluates competency in array manipulation, range updates, and feasibility under constraints, focusing on reasoning about sequential int...
Implement Kac ring with O(1) color and kstep
You are implementing a Kac ring dynamical system. Model - There are N positions arranged in a circle, indexed clockwise: 0, 1, ..., N-1. - Each positi...
Solve matrix diagonal and sliding-window statistics
Solve matrix diagonal and sliding-window statistics 1) Given an m x n integer matrix, determine whether every top-left to bottom-right diagonal has th...
Group Duplicate Files by Content
Group Duplicate Files by Content Given a snapshot of files, return groups of paths whose complete contents are identical. The interview report preserv...
Solve String Addition and Expression Evaluation
This question evaluates string manipulation and parsing skills for numeric computation, covering addition of integers represented as character arrays ...
Process auth requests with fraud rules
Question Implement a function that, given a list of Authorization Requests (timestamp_seconds, unique_id, amount, card_number, merchant), outputs a hu...
Simulate document assignment to indexers
You are given a system with m parallel indexers (workers), numbered from 0 to m-1. Documents arrive over time and are placed in a processing queue. Ea...
Evaluate an Arithmetic Expression
Evaluate an Arithmetic Expression Implement a function that evaluates a valid arithmetic expression containing non-negative integers, the binary opera...
Determine Whether a Binary Tree Is a Valid BST
Determine Whether a Binary Tree Is a Valid BST Problem Given a binary tree, determine whether the entire tree satisfies the strict binary-search-tree ...
Solve Subarray Sum and Local Minimum
Two coding problems were reported in the same phone-screen round: 1. Count target-sum subarrays. Given an integer array nums and an integer k, return ...
Highlight Exact Source Matches
You are given a string text and a list of strings sources. For every exact occurrence of any string in sources within text, wrap the matched character...
Design order stream with state transitions
Design order stream with state transitions Implement an in-memory order stream service with operations: add(order), delete(order_id), pause(order_id),...
Implement a sliding-window rate limiter
Implement an in-memory sliding-window rate limiter. You are given a stream of requests, each with a timestamp in milliseconds. Part 1: Per-user limit ...
Build the Largest Available Sequence
This question evaluates algorithmic problem-solving skills in state simulation, constrained selection, and lexicographic sequence maximization, measur...
Compute minimum path sum in a triangle
This question evaluates proficiency in dynamic programming and algorithmic problem-solving within the Coding & Algorithms domain, focusing on handling...
Compute unique-substring length and first unique index
This question evaluates proficiency in string processing and character-frequency reasoning by combining tasks that measure longest distinct-character ...