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."
Determine Complete Interval Coverage
You need to process a stream of real-valued points on a one-dimensional target segment from 0 to 50. Each time a point x arrives, it contaminates the ...
Fill rooms with nearest-gate distance
You are given an m×n grid representing a building floor plan: - -1 = wall/blocked cell - 0 = gate - A large positive number (e.g., INF = 2^31-1) = emp...
Solve maze reachability and two follow-ups
This set of tasks evaluates graph and state-space search with constrained movement (maze rolling ball), tree algorithms and recursion for computing di...
Detect and remove matched words in a char stream
This question evaluates understanding of online stream processing, substring matching, and the use of efficient data structures and algorithms for rea...
Implement a Cache Snapshot Printer
Implement an LRU-style cache and a snapshot-printing feature. The cache stores key-value pairs and has a fixed capacity. It should support normal cach...
Calculate Daily Driver Pay
You are given a one-day event log for a delivery driver. Each input record is a JSON event with fields such as order_id, event_type, timestamp, and ba...
Can You Reach the Last Index?
This question evaluates a candidate's understanding of array traversal and reachability in sequences of jumps, along with the ability to reason about ...
Find the nth prime number
Given an integer n (1-indexed), return the n-th prime number (e.g., n=1 -> 2, n=2 -> 3, n=3 -> 5). Design an algorithm that is efficient for moderatel...
Compute ways to climb n steps
Implement a function that returns the number of distinct ways to reach the top of a staircase with n steps if you can climb either 1 or 2 steps at a t...
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...
Find the second most frequent tag
You are given a list of strings in the following repeating order: [id1, name1, tag1, id2, name2, tag2, ...] So every 3 consecutive elements describe o...
Implement a multi-button click detector
Implement a click detector for multiple physical buttons. You receive button state updates as a stream. Each update provides: - button_id (integer) - ...
Find missing numbers in sequences
This question evaluates sequence pattern recognition, numerical reasoning with integers and rational numbers, and the ability to infer recurrences or ...
Compute 5-minute rolling average load
This question evaluates understanding of sliding-window aggregation and efficient data-structure design for time-series event streams, focusing on com...
Build next-word predictor with O(1) lookup
This question evaluates skills in language modeling, data structures, algorithmic optimization, and probabilistic sampling, within the Coding & Algori...
Output lexicographically largest DFS traversal
You are given a graph with n nodes labeled 1..n and m edges. Assume an undirected graph unless stated otherwise. You must output a node visitation seq...
Count all palindromic substrings
Given a string s, count how many substrings of s are palindromes. - A substring is a contiguous block of characters. - A palindrome reads the same for...
Maximize weighted sum with disjoint adjacent swaps
You are given an integer array arr of length n (0-indexed). Define the weighted sum as: S = Σ_{i=0..n-1} arr[i] * (i + 1). You may perform any number ...
Implement Table Aggregation
You are given a table represented as a list of rows. Each row contains: - key: a string identifying a group - value: an integer Write a function that ...
Find Missing Ranges with Bounds
Given a sorted array of distinct integers nums and two integers lower and upper that define an inclusive interval [lower, upper], return all maximal r...