Software Engineering Fundamentals Interview Questions
Practice 603 real Software Engineering Fundamentals interview questions for 2026. Covers core coding, data structures, complexity analysis, debugging, and implementation best practices — real questions from actual interviews with detailed solutions to support focused interview preparation. This category tests the engineering basics interviewers rely on to predict on-the-job performance: correct and efficient algorithms, clean and maintainable code, complexity trade-offs, edge-case reasoning, and the ability to turn requirements into a working implementation under time pressure. Expect heavy weighting at companies like Amazon, Google, and OpenAI, where fundamentals often gate candidates before system design or product rounds. To prepare, prioritize timed problem practice that enforces clear communication, complexity justification, and test-case coverage; drill common data structures and complexity patterns until they become second nature; and rehearse coding on a whiteboard or shared editor to simulate real loop conditions.
"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."
Implement Spreadsheet Cells with Dependencies
Design spreadsheet-like get and set operations for cells where formulas can depend on other cells. When a cell changes, dependent cells should reflect...
Reason About and Validate Virtual Card Transactions
Reason About and Validate Virtual Card Transactions A virtual-card transaction contains a 16-digit card_number, an 8-digit transaction_id, and an inte...
Implement an Accessible Autocomplete Search Component
Implement an Accessible Autocomplete Search Component Build a frontend autocomplete search bar from a supplied visual design. As the user enters text,...
Repair and Extend a Transaction Reward Processor
Repair and Extend a Transaction Reward Processor An existing layered web service has failing unit tests. Its transaction-processing path must read a t...
Build a Chainable Rectangle Manipulation API
Build a Chainable Rectangle Manipulation API You are given a page containing a 3-by-3 grid of rectangle elements and a JavaScript class whose methods ...
Implement a Synchronized First-Available Seat Allocator
Implement a Synchronized First-Available Seat Allocator Implement the core of a concurrent ticket-booking service with N seats numbered 1 through N. S...
Reason About Endianness, Ring Buffers, and Stack Behavior in Firmware
Reason About Endianness, Ring Buffers, and Stack Behavior in Firmware You are reviewing low-level firmware that receives binary records, buffers them ...
Build a Virtualized React Spreadsheet with Cell Formulas
Build and explain a React spreadsheet in four incremental parts. Focus on correct state flow and rendering behavior rather than visual polish. Clarify...
Minimize Array Amplitude After Removing a Contiguous Block
Given an array of integers and an integer K, remove exactly K contiguous elements so that the amplitude of the remaining array, defined as max(remaini...
Implement a Per-IP Sliding Window Rate Limiter
Given sorted request timestamps, matching IP addresses, a request limit, and a time-window length, return an array where 1 means the request is accept...
Reason About C Pointer and Array Declarations
Explain the following C declarations and expressions. Assume int objects and ordinary pointer arithmetic. 1. Declare an array of pointers to int. 2. D...
Clarify and Prune an N-ary Tree to a Depth Limit
You are given a rooted N-ary tree and a nonnegative integer k. First compute the tree's maximum depth. Then discuss how to delete a minimum set of nod...
Count Matrix Cells Whose Row and Column Neighbors Match
Given a matrix, count how many cells have the property that every other value in the same row and every other value in the same column are all equal t...
Design Extensible Undo and Redo for a Spreadsheet
Design Extensible Undo and Redo for a Spreadsheet A spreadsheet already supports editing one cell and needs undo and redo. Extend the design to row an...
Explain JavaScript Scope, Closures, Timers, and the Event Loop
Explain JavaScript Scope, Closures, Timers, and the Event Loop Answer the following JavaScript runtime questions precisely. Distinguish the language e...
Backend Fundamentals Deep Dive: MySQL Internals, Redis, and the HTTP/HTTPS Request Lifecycle
This question tests deep backend engineering knowledge across three core domains: MySQL InnoDB internals (logging, indexing, isolation), Redis persist...
Use find, ps, top, and kill Safely on Linux
Use find, ps, top, and kill Safely on Linux You are diagnosing a Linux host where an application is consuming unexpected resources and may need to be ...
Explain Core Python Runtime and Language Concepts
Explain Core Python Runtime and Language Concepts Answer the following Python questions as if you were reviewing production code. Use small examples w...
Implement DeleteTree With Limited Filesystem APIs
Review a filesystem implementation problem that asks you to delete an entire tree using only limited list, delete, and directory-check APIs. The quest...
Design Insert/Delete/GetRandom with Weighted Sampling
Design a data structure that supports inserting values, deleting values, and returning a random value. Then extend it so each inserted value has a wei...