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."

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"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."

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"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 a Shape interface using OOP
This question evaluates a candidate's competency in object-oriented design and implementation, covering concepts such as interfaces, encapsulation, po...
Build a Concurrent Recurring Job Scheduler
Design a thread-safe recurring job scheduler with concurrent schedule and deschedule operations. Specify timing semantics, cancellation races, stale e...
Investigate High Memory Usage
You are the on-call engineer for a delivery platform. System context - Couriers use a mobile app to accept and complete deliveries. - The mobile app c...
Review Code for Memory Risks
This question evaluates competency in memory management, performance analysis, and code-review skills for frontend implementations that deduplicate ob...
Compare processes and threads in Linux and Python
Explain the differences between a process and a thread in Linux. Then explain how Python differs (e.g., the GIL), and when you would use Python thread...
Explain code complexity and design two games
You are given three independent interview prompts. 1) Code comprehension & complexity - Given two short code snippets (language-agnostic), explain in ...
Design poker-like hand comparison with custom ranking
Problem Design an object-oriented solution to compare two players' hands in a card game similar to poker. You are given two hands (each a fixed number...
Build a React naval board
Build a simplified, single-player Battleship-style game board in React. There is no opponent, no turn-taking, and no networking — you are implementing...
Explain DB concurrency, debugging slowness, DDD and CQRS
Backend fundamentals: concurrency, performance investigation, and architecture terms Answer the following backend questions: 1. How do databases handl...
How do you review a design document?
This question evaluates proficiency in reviewing design documents, including requirements and scope, architecture and data flow, correctness and secur...
Implement tail -n for a Very Large File
Implement tail -n for a Very Large File Design and implement the core of tail -n: given a seekable file and a non-negative integer n, return the final...
How do you conduct a code review exercise?
In a live interview, you are shown a short code change — a diff, a pull request, or a standalone function — and asked to produce written code review c...
Design several backend components
This set of prompts evaluates backend system design, API and data-modeling skills, low-level software architecture, and competencies in consistency, c...
Build a Reliable Streaming Chat UI
You are building a React-based chat interface where assistant responses stream into the UI token by token in real time (the same UX as a typical LLM c...
Implement a Credit API Workflow
You are given documentation for a sandbox credit-management API. The documentation describes API operations for creating an account, adding credits, c...
Design a Parking Garage Object Model
Design an object-oriented model for a multi-level parking garage. The garage should support: - Multiple floors and parking spots. - Different vehicle ...
Implement CRUD API and tests
You are given two software-engineering tasks. 1. Implement a simple REST API for a resource such as Note or Message. - Support basic CRUD operation...
Design an Extensible Simulation Engine
This question evaluates object-oriented design, state modeling, API design, modularity, testability, and the ability to architect an extensible simula...
Explain C++ References, Pointers, Virtual Methods, and Overrides
Prepare for a Zoox software engineering interview question about explain c++ references, pointers, virtual methods, and overrides. The prompt highligh...
Explain Out-of-Bounds Bugs and Infinite Loops
You are given a C or C++ code snippet that behaves incorrectly. The root cause is an out-of-bounds memory access, such as reading or writing past the ...