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."
Solve Quickselect, Tree Distance, and Prefix Substrings
You are given three independent coding tasks. 1. Implement Quickselect - Given an unsorted integer array nums and an integer k, return the k-th sma...
Design a Distributed Crossword Solver
Design an online service that solves crossword-like word puzzles. A user submits a puzzle description that includes the grid layout, blocked cells, an...
How Would You Optimize a Program
You are given an existing program that produces correct results but is too slow in production. Describe a structured plan to optimize it. Your answer ...
How do you handle an LLM agents interview?
You have an interview on your agenda titled “Agents Interview.” Explain how you would approach this interview if it is about designing and evaluating ...
Improve concurrency beyond a single lock
You are given a simple multi-threaded component that protects all shared state with a single mutual-exclusion lock (mutex). Scenario A service has man...
Design Catalog Update Pipeline
Design a system that takes a very large product catalog, for example 500 million records, and propagates updates to all downstream internal systems. E...
Design access control and heartbeat systems
Design two backend systems. Part A: Door access control system Design a service that manages which people can open which doors. The system must suppor...
Explain virtual machines and concurrency basics
Topics Answer at a senior-engineer depth. Use diagrams or step-by-step reasoning as needed. 1) Virtual machines (VMs) - What is a VM and what problem ...
Design an Async Job Scheduler
Design an asynchronous job scheduler service. The service must support two job types: 1. Immediate jobs: submitted jobs that should run as soon as pos...
Design API for split-stay combinations
Question Design an HTTP API endpoint that, given a requested date range and a collection of Airbnb listings with their availability, returns all valid...
Predict most likely next word from training data
You are given tokenized training data consisting of multiple sentences (each sentence is a list of words). Build a lightweight model/data structure th...
Debug a slow concurrent network server under load
Scenario You are on-call for a high-throughput network service (e.g., a TCP/HTTP server). Under load, users report: - Throughput suddenly drops - p99 ...
Flatten a nested JSON object
Problem You are given a JSON-like value representing an object that may contain: - Objects / dictionaries (string keys) - Arrays / lists - Primitive v...
Design a 3-day donation platform
Design: Online Donation Platform for 3-Day Campaigns Context Design an online donation platform optimized for short, 3-day fundraising campaigns. Each...
Implement an in-memory SQL-like table
Implement a simplified in-memory SQL-like database for a single table. You should support the following operations on a table with a fixed schema (a l...
Maximize Value Under a Budget
You are given an array of items. Each item has a price and a value, and you are given a total budget. Each item can be purchased at most once. Impleme...
Merge overlapping time intervals
Problem: Merge Intervals You are given an array of intervals intervals, where each interval is a pair [start, end] with start <= end. Merge all overla...
Design an alert notification system
Design a multi-tenant alert notification system for operational incidents. Monitoring sources send events when checks fire or recover. Users can confi...
Implement Chat Event Counter
Design an in-memory counter for chat activity. You need to implement a class with the following two methods: `text processEvent(userId: string, chatId...
Answer common recruiter behavioral questions
In an initial recruiter phone screen, you are asked several standard questions. Prepare structured, interview-ready responses for: 1) Why are you look...