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."
Maintain the Median of a Data Stream
Maintain the Median of a Data Stream Process a stream of integers and return the median after every insertion. For an odd number of values, the median...
Implement consistent hashing ring
Implement consistent hashing ring Implement consistent hashing for routing keys to servers. Provide APIs addNode(nodeId, weight), removeNode(nodeId), ...
Detect a Winner on a 3x3 Tic-Tac-Toe Board
Detect a Winner on a 3x3 Tic-Tac-Toe Board Implement tic_tac_toe_winner(board) for a completed or partially completed 3x3 board. Each cell is "X", "O"...
Palindrome After Deleting at Most One Character
This question evaluates a candidate's ability to reason about two-pointer string traversal and palindrome verification under a single edit constraint....
Return Top K Open Businesses
This question evaluates a candidate's ability to perform filtering and multi-criteria ranking, requiring correct handling of an open-status filter and...
Find the First Bad Version in a Monotonic Release History
Find the First Bad Version in a Monotonic Release History You are given a release history as a boolean array bad. Versions use zero-based indices. Onc...
Reverse a Singly Linked List
Reverse a finite singly linked list represented by nested two-item Python lists. Reuse the existing node objects without allocating replacements, and ...
Merge Overlapping Collinear Segments
You are given a list of 2D geometric segments: vector<vector<pair<double, double>>> segments Each inner list represents one segment and contains at le...
Implement follow graph with snapshots and recommendations
Design and implement an in-memory “social network” component that supports following/unfollowing, point-in-time (snapshot) queries, and a simple recom...
Implement a Half-Open Interval Range Module
Implement a Half-Open Interval Range Module Implement a module that tracks subsets of the real-number line using half-open intervals [left, right). Pr...
Rewrite Sentence-Ending Punctuation
Rewrite Sentence-Ending Punctuation Transform a string in two conceptual steps: 1. Add one extra exclamation mark to every maximal run of existing ! c...
First Word Matching Each Prefix Query
This question evaluates a candidate's grasp of string data structures and efficient prefix-matching techniques, core competencies in coding and algori...
Reverse a Singly Linked List
This question evaluates a candidate's grasp of linked list pointer manipulation and in-place data structure transformation. It tests the ability to re...
Implement a Recipe Cart
This question evaluates the ability to design and implement stateful data structures and aggregation logic for tracking ingredient counts, applying ti...
Sort an RGB Record Collection In Place
This question evaluates a candidate's ability to implement an in-place, single-pass partitioning algorithm under strict interface constraints, commonl...
Implement streaming enrichment aggregator
This question evaluates competency in stateful stream processing, event-driven aggregation, in-memory state management, time-based expiry, and produci...
Design a trie-based URL router with wildcards
Design a trie-based URL router with wildcards Implement a URL routing matcher that supports adding route patterns and matching request paths, using a ...
Implement a Cloud Storage Service
Implement an in-memory cloud storage system. Build the class incrementally; later levels must preserve all behavior from earlier levels. File names ar...
Solve a 9x9 Sudoku puzzle
Given a partially filled 9×9 Sudoku board, fill the empty cells so that the completed board is valid. A valid Sudoku satisfies: - Each row contains di...
Implement cache and gift assignment system
You are given two independent programming problems. --- Problem 1: Implement a bounded key–value cache Design a data structure that stores key–value p...