Software Engineer Interview Questions
Practice 4,229 real Software Engineer interview questions for 2026 — real questions from actual interviews with detailed solutions to speed your interview preparation. This collection reflects what top tech firms like Meta, Amazon, Google, DoorDash, and TikTok typically evaluate: rigorous coding and algorithmic problem solving, increasing expectations for end-to-end system design (including GenAI/LLM design at some teams), clear complexity analysis, and reliable engineering judgment under constraints. Expect a multi-stage pipeline: recruiter screen, timed or asynchronous coding assessments, one-to-more live coding rounds focused on data structures and correctness, system-design conversations for mid and senior levels, and behavioral/hiring-manager interviews that probe ownership and collaboration. To prepare, prioritize patterned practice (timed mock interviews and implementation + optimization), learn scalable design frameworks, rehearse concise trade-off communication, and tailor examples to company signals like Amazon’s leadership lens or product/latency focus at delivery and media-driven teams. Consistent, feedback-driven practice that combines problem-solving speed, clean code, and measured design reasoning is the quickest path to offers.
"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."
Find the Highest-Cost Top-Level Job
You are given a local JSON file, jobs.json, containing an array of background job records. Each record has: - id: a unique job identifier - parent_id:...
Implement Memory Allocation and In-Memory Records
Solve the following two implementation problems. Problem A: First-Fit Memory Allocator You are given a contiguous block of memory containing n units, ...
Implement Minesweeper and Word Search
Solve the following coding problems. Problem 1: Generate and Print a Minesweeper Board You are given integers rows, cols, and mineCount. Generate a ro...
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 ...
Explain ACID and transactions
ACID Transactions: Definitions, Enforcement, Isolation Levels, and Example Context You are designing a service backed by a relational database that su...
Implement matrix transforms and discuss eigenvalues
You are given a square matrix A (size n × n). 1. Diagonal symmetry (transpose): Transform A into its transpose (mirror across the main diagonal). Pref...
Validate password strength and repair
Given a password policy—length between 8 and 20 characters; must include at least one lowercase letter, one uppercase letter, and one digit; and must ...
Design Slack-like multi-tenant global messaging system
Design a team messaging platform similar to Slack that supports multiple organizations (multi-tenancy) and is deployed globally. Functional requiremen...
Design a Dormitory Room-Assignment System (OOD)
You are asked to design the object-oriented model for a dormitory room-assignment system. You are given a set of students and a set of rooms. Each roo...
Check whether a string is a palindrome
Problem Given a string s consisting only of lowercase English letters (a-z), determine whether s is a palindrome. A palindrome reads the same forward ...
Solve common string and subarray problems
You are given three coding tasks: 1) Reverse a string - Input: a string s. - Output: the string with characters in reverse order. 2) Maximum sum of a ...
Find numbers with exactly two sum-of-squares forms
Given an integer \(n\), find all integers \(s\) such that \(0 \le s < n\) and \(s\) can be expressed as a sum of two squares in exactly two distinct u...
Answer rapid-fire behavioral questions
Answer rapid-fire behavioral questions In the DoorDash software engineer technical screen, you are asked to answer a rapid-fire battery of behavioral ...
Implement a thread-safe producer–consumer buffer
Implement a thread-safe producer–consumer buffer Bounded Blocking Buffer with Shutdown and Timeouts You are asked to design and implement a thread-saf...
Compute max simultaneous drivers last 24 hours
Given delivery intervals (driverId, startTime, endTime) already recorded, implement maxSimultaneousDriverInPast24Hours() that returns the maximum numb...
How would you answer a recruiter screen?
You are on a 20–30 minute recruiter intro call for a software engineering role. The recruiter asks the following questions: 1. “Tell me about yourself...
Find Longest Activatable Server Streak
You are given a binary array serverStates, where 1 means a server is currently on and 0 means it is off. You may turn on at most k currently off serve...
Design a cloud database write path and recovery
System Design (Engine-level): Write Path + Crash Recovery Design a core subsystem for a cloud-native relational database (Aurora-like) where compute i...
Return a topological ordering of a graph
Problem: Output a topological ordering Given a directed graph with n nodes labeled 0..n-1 and a list of directed edges edges, return a topological ord...
Diagnose why a scaled system became slow
You are on-call for a production service that recently scaled up (more instances, more users/traffic). After the scale-up, users report the system is ...