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."
Make a Parentheses String Valid
Given a string s containing lowercase English letters and the characters '(' and ')', remove the minimum number of parentheses so that the resulting s...
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...
Debug Kubernetes crashes and review Python ingestion script
Part A — Kubernetes: Pod/Container Crash Debugging You are on call and a service deployed to Kubernetes starts failing. The Pod shows CrashLoopBackOff...
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...
Find minimum cycle cost per node
Problem You are given a weighted directed graph with n nodes labeled 0..n-1 and m directed edges. Each edge is (u, v, w) meaning you can go from u to ...
Find minimum moves to solve the 15-puzzle
Problem Given a 4×4 sliding puzzle (the classic 15-puzzle), compute the minimum number of moves required to reach the solved state, or return -1 if it...
Design webhook, POI, chat, CI/CD, payments
You are asked to design several large-scale backend systems in a single onsite session. The bar is breadth and judgment under time pressure: for each ...
Design a payment system
Design a payment system for an online commerce platform. The system should support: - Creating a payment order for a purchase - Authorizing and captur...
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...
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...
Design async batched key-value fetcher
Design an async, batched key-value fetcher with a 100 ms window Context You have a single-threaded, event-loop environment (e.g., JS/TS). A backend en...
Design low-latency large-scale hotel booking system
You are asked to design the backend for a large-scale hotel booking system that runs behind a very high-traffic consumer app (think a TikTok-like app ...
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...
Solve small string and API tasks
You are given three small programming tasks (typical “easy” difficulty). Implement each as a function. Task 1: Validate parentheses Given a string s c...
Describe your most memorable bug and fix
Tell me about the most memorable/impactful bug you encountered in a project. Include: - What the system/project was and your role - How the bug manife...
Solve restaurant path and order event tasks
You are given two independent coding tasks. Task 1: Shortest paths in a restaurant grid Context: A restaurant is represented as a 2D grid. The waiter ...
Design a large-scale ticketing system
Design an online ticketing system similar to Ticketmaster that supports very high concurrency for popular events where many users try to purchase tick...
Implement a Coin-Constrained Jump Strategy
You are implementing an autopilot strategy for a simple side-scrolling jump game. A character moves forward automatically. On each game tick, your str...
Implement a multi-level digital recipe manager
Implement a RecipeManager class for a digital recipe manager. The task is progressive (Levels 1–4). You can assume a single-process in-memory implemen...