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."
Build an Accessible Recursive Expand-and-Collapse Tree in React
Build an Accessible Recursive Expand-and-Collapse Tree in React Implement a React component that renders hierarchical data with + and - controls for c...
Design Stack Evaluators and Low-Latency Memory Primitives
Work through the following systems-programming exercises. State the memory and concurrency model you assume before writing pseudocode. Part 1: Stack M...
Implement A Mobile Chat Interface In An Existing Codebase
You are given an existing mobile codebase and asked to implement a ChatGPT-style chat screen in about 40 minutes. Describe how you would read the proj...
Turning Interview Code into a Reusable Library or API
You have just finished implementing a small game engine during a coding interview: a board data structure for a two-player piece-dropping game, a func...
Split a Message into Length-Limited Parts with Numbered Suffixes
Given a message string and a length limit, split the message into ordered parts. Each part must end with a suffix like <X/Y>, where X is the 1-based p...
Design a Bank Account OOP Simulation with Transfers, Payments, and Merges
Design an object-oriented banking simulation. Accounts can be created, balances can be queried, money can be transferred, payments can be recorded, an...
Explain GPU Memory And Matrix Transpose Optimization
Study GPU software engineering fundamentals through concepts like warps, registers, shared memory, coalescing, cache behavior, tiling, and matrix tran...
Design a 2048 Game
Design the object model and core game logic for a 2048 game on an N x N grid. This is an object-oriented design problem: focus on the classes, their r...
Java, Spring & Kafka Fundamentals Deep-Dive
This question tests depth of knowledge across core Java, Spring Boot, and Kafka fundamentals commonly required for senior backend engineering roles. I...
Build a Durable Key-Value Cache
This question evaluates understanding of data durability and recovery mechanisms, including write-ahead logging, in-memory caching, operation ordering...
Implement a Single-Screen Tic-Tac-Toe Game with State Management
Implement a single-screen Tic-Tac-Toe game. Maintain game state, support player moves, detect wins and draws, prevent invalid moves, and keep the impl...
Debug and Extend a Priority-Aware Python Thread Pool
Debug and Extend a Priority-Aware Python Thread Pool You inherit a Python thread-pool implementation that accepts callables and runs them on a fixed n...
Explain KV cache in Transformer inference
Question In Transformer-based large-language-model inference, what is a key-value (KV) cache? Give a complete, systems-level explanation that covers: ...
Implement Layered Endpoint and Global Rate Limits
Design an in-process rolling-window rate limiter that enforces both per-endpoint and backend-wide limits atomically. Examine boundary semantics, concu...
Diagnose Cold-Load and Massive-Table Performance in a Web App
Diagnose Cold-Load and Massive-Table Performance in a Web App You are reviewing two frontend performance problems. Explain how you would measure each ...
Debug a Concurrent Job Scheduler
You are handed a buggy Python job scheduler that runs many independent jobs concurrently. Each job has an ID, a callable to execute, a maximum retry c...
Design and Implement a Cross-System Object Tracker
Design and Implement a Cross-System Object Tracker Prompt Two independent systems, A and B, observe real-world objects. Each system assigns its own un...
Validate a Third-Party Identity Payload
Validate a Third-Party Identity Payload A third-party service returns a JSON payload with a fixed documented structure. The first subject contains a V...
Process Delimited Product, Promotion, and Shelf Records
Process Delimited Product, Promotion, and Shelf Records You are given product records such as a100|apple|6|123, where the fields are SKU, name, quanti...
Design a Versioned Recipe Store with Search and Rollback
Prepare for a The Trade Desk software engineering interview question about design a versioned recipe store with search and rollback. The prompt highli...