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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"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."
Implement tail N lines
Question Implement a utility tail(path: string, N: int) (and an equivalent stream variant) that prints the last N lines of input without loading the w...
Build Prefix Lookup with a Trie
Build prefix lookup for repeated queries. Given words and query prefixes, return matching words for each query in lexicographic order. Implement: `pyt...
Compute Max Pooling Values and Coordinates
Practice a Waymo coding interview problem focused on compute max pooling values and coordinates. The prompt emphasizes edge cases, clean implementatio...
Implement a Searchable Logger Pipeline
This question evaluates proficiency in software design, data structures, and algorithmic text search by requiring a transformation pipeline, ordered i...
Sum palindrome-change costs over all substrings
This is a three-part coding screen. Each part is independent — a string-algorithms problem, a SQL aggregation problem, and a shell-parsing problem — a...
Count Digit-Reversal Equivalent Pairs
Define flipdigits(x) as the integer produced by reversing the decimal digits of non-negative integer x and removing leading zeroes from the reversed r...
Calculate Completion Time for a Single-Server Reactor Queue
A laboratory has one molecular reactor. Each accepted sample takes exactly 5 minutes to process. Samples arrive throughout the day at integer timestam...
Implement Task Management and Duplicate Detection
This question evaluates implementation and system-design skills across two problems: an in-memory task management service (CRUD operations, prioritize...
Solve four classic algorithm problems
You are given four independent coding tasks. For each task, implement the required function. --- Problem 1: Zigzag level-order traversal of a binary t...
Implement custom iterator classes
Implement custom iterator classes In a blank coding environment (no IDE assistance, no autocomplete), implement an iterator abstraction entirely from ...
Implement local maxima, bagging, and k-means
This question evaluates skills in algorithm implementation and machine learning fundamentals—specifically streaming local maxima detection, bootstrap ...
Implement flood fill using BFS and DFS
This question evaluates proficiency in graph traversal and matrix manipulation, specifically the implementation of BFS and DFS variants for flood fill...
Solve two array and string problems
You will solve two independent coding tasks. Problem 1: Generate All Subsets of a Set You are given an integer array nums containing n distinct elemen...
Solve two interval array problems
You are given two interval-based tasks from a technical screen for a data engineering role. 1. Merge overlapping intervals - Input: an array of int...
Terminal-Controlled Grid Rover Simulator
This question evaluates a candidate's ability to model stateful simulation logic, translating grid coordinates, heading rotations, and sequential comm...
Group movies via graph traversal
You are given n movies labeled 0..n-1 and a list of undirected pairs (a, b) meaning movies a and b are similar. Group all movies into categories where...
Simulate Transaction Lock Scheduling
This question evaluates understanding of concurrency control, lock scheduling, transaction state management, and queuing behavior in the Coding & Algo...
Implement IP Address Arithmetic
This question evaluates proficiency in IP addressing, parsing and validation, binary/address-space arithmetic, CIDR subnet calculation, and formatting...
Minimize Increments to Equalize Path Costs
This question evaluates understanding of tree data structures, root-to-leaf path aggregation, and cost-balancing strategies within the Coding & Algori...
Assign Meetings and Find the Most-Used Room
Assign Meetings and Find the Most-Used Room There are n rooms numbered from 0 through n - 1 and meetings [start, end] with distinct start times. Proce...