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."
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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."
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Implement a Simplified std::vector with Manual Memory Management
This question evaluates a candidate's grasp of low-level memory management in C++, including the distinction between raw allocation and object constru...
Design a Concurrent Key-Value Store with Batch Writes
Design a Concurrent Key-Value Store with Batch Writes Design the core implementation of an in-memory key-value store for concurrent callers. For this ...
Design an In-Memory Pub-Sub Model
Design an object-oriented, in-memory publish-subscribe model. Requirements: - A publisher can publish a message to a topic. - A subscriber can subscri...
Design an extensible poker-hand evaluator
Design and implement an object-oriented solution for a simplified two-player poker-like game called Camel Cards. The interviewer is explicitly evaluat...
Debug a Python Aggregation Loop with Dictionaries and Lists
Review a Python aggregation routine that uses dictionaries, lists, and loops, then explain how you would make it correct and robust. This interview ex...
Find the Longest Common Digit Prefix Across Two Arrays
Given two arrays of positive integers, convert each integer to its decimal string representation and find the maximum length of a common prefix betwee...
Reason About a Movie Billboard Rotation Component
Reason About a Movie Billboard Rotation Component An interview exercise concerns a movie billboard rotation component. The retained description says n...
Reconcile Records Across Sources
In an AI-assisted ("AI coding") interview round, you are asked to reconcile person records across multiple data sources. Each source contains records ...
Design an advertiser metrics tracking platform
This question evaluates object-oriented design competencies such as domain modeling, class responsibilities and relationships, service interfaces, ext...
Trace Virtual Address Translation Through TLBs, Page Tables, and Caches
Trace Virtual Address Translation Through TLBs, Page Tables, and Caches Explain how a CPU translates a virtual address to a physical address in a page...
Evolve Cursor Pagination Without Breaking Clients
Debug bidirectional cursor pagination when many transactions share the same timestamp, then add amount sorting without breaking old clients. Define st...
Design a Write-Ahead Log Writer with Batch Writes
Design a Write-Ahead Log Writer with Batch Writes Design the low-level behavior of a write-ahead log writer that accepts records from concurrent calle...
Design and Implement an Idempotency Layer for Order Creation
Design an idempotency layer above an order creation service so duplicate client retries do not create duplicate orders. `hint Hint 1 Start by stating ...
Design a Thread-Safe Bounded Blocking Queue
Design a Thread-Safe Bounded Blocking Queue Design a fixed-capacity FIFO queue shared by multiple producer and consumer threads. Provide operations eq...
Trees and Binary Search Trees: Taxonomy, Invariant, and Traversal/Search
This question evaluates a candidate's grasp of tree data structures and the binary search tree ordering invariant, along with the ability to implement...
Build a Transaction CSV Cleaning Pipeline
This question evaluates skills in data engineering and software engineering fundamentals, focusing on designing deterministic, auditable batch ETL/cle...
Debug and Improve a Load Balancer
Debug and Improve a Load Balancer Clarifying Questions to Ask - Is the load balancer a single process exercise or a distributed production service? - ...
Analyze the Fairness of an Incremental Shuffle
Consider the following function, where random() returns an independent value uniformly distributed in [0, 1) on every call: `javascript function shuff...
Debug and Extend Cursor Queries
You are in an AI-assisted coding interview. You may consult AI-generated suggestions, but you are expected to validate them, explain your reasoning ou...
Test and Run a Reproducible Data Science Pipeline
Design unit and integration tests for a Python data science pipeline that loads data, builds features, trains a model, and writes predictions. Add a r...