Software Engineer Interview Questions
Practice 5,054 real software engineer interview questions for 2026. Covers top employers like Google, Amazon, OpenAI, and Uber — real questions from actual onsites with detailed solutions — and is built for focused interview preparation. This collection emphasizes coding and algorithms first, then system design, performance, and role-specific domains so you can train the exact skills interviewers test. What’s distinctive: coding rounds still dominate at every company, Google often emphasizes algorithms and distributed-systems thinking, Amazon commonly probes scalable-services design and operational tradeoffs, OpenAI leans toward ML systems, model deployment and inference-scaling problems, and Uber typically asks real-time routing, geospatial and consistency challenges. Expect live coding, pair-programming, and whiteboard/system-design sketches. To prepare efficiently, drill medium-to-hard algorithm problems with time limits, practice end-to-end system design sketches focused on capacity and reliability, and rehearse concise behavioral stories that show ownership and impact.
"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."
Describe std::string copy semantics
Describe std::string copy semantics In C++, what happens with std::string when you write: std::string a = "123"; std::string b = a; Describe which ope...
Compute binary tree diameter
Compute binary tree diameter Given the root of a binary tree, compute the tree's diameter defined as the maximum number of edges on any path between t...
Compute max-ons and deletion indices
Question Given a circular array of n computers represented by 0 (off) and 1 (on), determine the maximum possible number of on computers within any con...
Solve binary-search knapsack & graph shortest path
Question Given a sorted list of items, design an efficient solution (using binary search) to achieve the target objective instead of a dynamic-program...
Solve Number of Islands
Question LeetCode 200. Number of Islands – Given a 2D grid of '1's (land) and '0's (water), count the number of islands. Follow-up: implement the solu...
Find duplicate files by size
Question LeetCode 609. Find Duplicate File in System — find duplicate files using file size instead of content comparison https://leetcode.com/problem...
Delete duplicate files via DFS
Question LeetCode 609. Find Duplicate File in System – Implement an algorithm (using DFS/backtracking) to delete files with duplicate content in a fil...
Implement Connect Four game
Question Design and implement the Connect Four game board, player moves, and winner-detection logic. Discuss time/space complexity and possible follow...
Handle invalid Lisp expression parsing
Question LeetCode 736. Parse Lisp Expression – Given a string representing a Lisp-like expression containing let/add/mult operations and variable bind...
Count interval intersections
Question For a list of n segments, where each segment i has start[i] and end[i], compute for every segment the count of other segments that intersect ...
Compute delay times in priority array
Question Given an array of integers representing task priorities processed from right to left, return an array where each element is the distance (ind...
Solve Open the Lock BFS
Question LeetCode 752. Open the Lock – Given an initial lock state "0000", a target combination, and a list of deadend combinations that cannot be use...
Implement test failure analytics APIs
Question Design a data structure that supports: log(testId, timestamp, status) — record the status ('pass'/'fail') of a test run; timestamps are stric...
Count subarrays with ≥k identical pairs
Question LeetCode 2537. Count the Number of Good Subarrays – Given an integer array nums and an integer k, return the number of contiguous subarrays i...
Solve non-repeating show substring
Question LeetCode 3. Longest Substring Without Repeating Characters – variant where the elements are show names instead of numbers. https://leetcode.c...
Verify and modify inorder subsequence
Question Given a binary tree and a sequence of numbers, design an algorithm to check in O(n) time and O( 1) extra space whether the sequence is a subs...
Determine reachability and optimize task scheduling
Question LeetCode 780. Reaching Points: Given four integers a, b, c, d (1 <= a, b, c, d <= 1000). Starting from (a, b) you may repeatedly apply either...
Maximize vacation streak with PTO
Question Given an array of characters containing 'w' (workday) and 'h' (holiday) and an integer n representing the number of PTO days you can convert ...
Solve programming task with follow-ups
Question Pure programming problem solving: implement the core algorithmic solution, then extend it to ( 1) support a constraint of consecutive N eleme...
Convert integer to NAF form
Question Convert a given integer into its Non-Adjacent Form (NAF) representation such that no two non-zero digits are adjacent, and prove that the res...