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."
Design fast search for AV raw logs
Autonomous vehicles collect large volumes of raw logs (e.g., sensor streams, perception outputs, planning/debug signals). In these logs, there may be ...
How to settle multi-person debts in minimum transactions
Minimize Multi-Person Debt Settlement (Minimum Transactions) Given a set of loan/transfer records in the format: - transactions[i] = [from, to, amount...
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 CSAT Sliding Window Tracker
Design and implement a class that tracks customer satisfaction scores over a sliding time window. A customer support conversation has: - conversation_...
Implement a Batch Image Processor
Implement a program that applies basic image transformations to a batch of images. You are given a list of input image paths and, for each image, a se...
Maintain a Stream Median
Design a data structure for a stream of integers. It must support the following operations efficiently: - add_num(x): insert an integer x into the str...
Debug and Explain Fixes
Given a small codebase with failing unit tests, identify the root causes of the failures, fix the bugs, and explain the defects you found. Add minimal...
Design a Ticketmaster-like ticketing system
System Design: Online ticketing platform (Ticketmaster-like) Design a system that sells tickets for events (concerts/sports) with seat selection. Core...
Find longest substring with ≥k repeats
Problem You are given: - a string s (consisting of lowercase English letters), and - an integer k. Return the length of the longest contiguous substri...
Design Telehealth Consultation Queue
Design a web-based queuing application for a health-insurance company that offers free 24/7 telehealth access to its members through a website and mob...
Design a local activity counter service
System Design: Near-Real-Time Activity Counting Service Context Build a service that ingests high-throughput client events and provides near-real-time...
Implement a ring buffer
Implement a fixed-capacity circular buffer (ring buffer) supporting push, pop, peek, isEmpty, isFull, and size in O( 1) time using an array. Define an...
Discuss queues, NoSQL, and concurrency
System Design Concepts: Messaging, Storage Choices, and Concurrency Context: You are designing distributed services that communicate via events and mu...
Implement a minimal local HTTP server
Build a Minimal Local HTTP/1.1 Server (No Frameworks) Context You are asked to implement a minimal HTTP/1.1 server from scratch using only the standar...
Design distributed message queue service
Design a Distributed Message Queue Service Problem Statement Design a distributed message queue system that supports very high throughput for both pro...
Reverse Nodes in K-Sized Groups
Given the head of a singly linked list and an integer k, reverse the nodes of the list in contiguous groups of size k. Requirements: - Only complete g...
Design a URL Shortener
Design a URL shortening service similar to Bitly. The system should: - Accept a long URL and generate a short, unique alias. - Redirect users from the...
Design a News Aggregator
Design a news aggregation system that collects articles from many external news sources and serves a unified feed to end users. A key constraint is th...
Design in-memory trade subscription processor
You are asked to design and implement the internal logic of an in-memory trade subscription processor in C++. A simplified interface is provided: `cpp...
Compute longest common subsequence length
Problem You are given two strings s and t. A subsequence of a string is obtained by deleting zero or more characters without changing the order of the...