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."
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 ...
Design an autocomplete suggestions API
Problem: Autocomplete suggestions (Trie) You are building an autocomplete feature. Input - A dictionary of n unique words words[i] (lowercase a–z). - ...
Implement undo/redo with two stacks
Problem: Undo/Redo for a Simple Text Editor Design a data structure that simulates a very small text editor with undo and redo. You are given a sequen...
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...
Walk through project scope, ownership, and decisions
Walk through project scope, ownership, and decisions Behavioral: Walk Through a Significant Project (Technical Screen — Software Engineer) Provide a d...
Return a valid task order
You are given n tasks labeled from 0 to n - 1 and a list of prerequisite pairs prerequisites, where each pair [a, b] means task b must be completed be...
Find flush and straight groups in cards
You are given an array of strings cards, where each string represents a distinct playing card. Each card string has the format <rank><suit>: - rank is...
Find and Merge Camera Alert Intervals
You are given surveillance camera readings as time-series data. Each reading is a pair (timestamp, value), sorted by timestamp. A camera is considered...
Implement an in-memory database with TTL and backup
In-Memory Database (Levels 1–4: TTL and Backup/Restore) Implement an in-memory database that stores records identified by a string key. Each record co...
Answer behavioral questions about delivery and influence
Behavioral questions Prepare structured answers (e.g., STAR) to the following: 1. Complex problem, simple solution: Give an example of a complex probl...
Rotate a 3×3 digit grid by 180°
Problem You are given a 3×3 grid of digits (characters '0'–'9'), represented as an array of 3 strings of length 3. When the entire grid is rotated by ...
Construct a circular gift exchange across families
You are given a “big family” composed of several sub-families. Each sub-family is a list of unique person IDs/names. Example input: - [[A1, A2], [B1, ...
Design review system with voting and rewards
Design a Scalable Product Review System with Voting and Rewards You are designing a reviews feature for a large e-commerce marketplace. Customers can ...
Implement compile-time function type verification
Implement a C++20 compile-time utility to verify whether a callable matches a target function type. Requirements: create a primary template is_callabl...
Design streaming difference at scale
Design a Near Real-Time Anti-Join: Stream vs. Large Reference List You are given: - list1: an unbounded, high-throughput event stream of keys (e.g., u...
Calculate conditional probabilities for coin tosses
Probability with Two Fair Coin Tosses You toss a fair coin twice. Let the coin be fair (P(H) = P(T) = 1/2) and the tosses independent. (a) Compute P(s...
Design a scalable network I/O service
System Design: High-Volume Network I/O Backend (Files and Streaming) Context Design a backend service that supports millions of users uploading and do...
Scale crawler with thread pool
Concurrent Web Crawler — Bounded Thread Pool, Thread-Safe Frontier, Dedupe, Politeness, and Trade-offs You are refactoring an existing single-threaded...
Design and operate a monolith on Kubernetes
Design and Operate a Monolith on Kubernetes Context You are joining an infrastructure team. The backend is a single monolithic service. The company is...
How would you handle an unresponsive teammate?
Scenario You are working on a project with a hard deadline. A teammate who owns a critical task has become unresponsive (misses standups, does not rep...