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."
Design an Event-Driven CPU Overheat Controller
Design an Event-Driven CPU Overheat Controller Design an OverheatPreventionController that simulates multiple processor cores without physical sensors...
Design a Concurrent Restaurant Waitlist and Seating System
Design a Concurrent Restaurant Waitlist and Seating System Design a restaurant system with a configurable set of tables and a FIFO waitlist of parties...
Debug Watch List Movie Operations
You are given a full-stack Movie DB application. Users can log in, create, update, and delete watch lists, and add or remove movies from a watch list....
Design First-Fit and Best-Fit Memory Allocation
Design the core of a heap allocator over one contiguous managed region. Blocks have an address, size, and free/allocated state. Allocation requests sp...
Design Snapshot Set Iteration and Clarify Durable Writes
Work through a snapshot-set iterator and then explain how you would clarify a separate durable-writer exercise whose detailed contract has not been pr...
Prepare for Backend Parsing, API Integration, AI Coding, and Bug Fixing Rounds
Prepare for backend parsing, extensible class design, API integration, AI-assisted coding, bug fixing, and a hiring-manager round. `hint Hint 1 Start ...
Design a News Subscription Processing Engine
Design a news subscription processing engine with four core capabilities: receive a news item, add a subscription, remove a subscription, and publish ...
Make a Courier Pay Workflow Resilient to Downstream Failures
Make a Courier Pay Workflow Resilient to Downstream Failures A coding exercise has produced a simplified courier-pay calculator. The calculation rules...
Implement A Prioritized Task Scheduler With Parent Dependencies
Implement a task scheduler. Each task has an id, due date, create time, high-priority flag, assignee, completion status, description, and optionally a...
Design a Robust Feature Flag Evaluation Engine
You are given feature definitions and user records as JSON. Each feature flag has a key, an enabled switch, a default Boolean, and an ordered list of ...
Deduplicate and Order Batch and Streaming Logs
Deduplicate and Order Batch and Streaming Logs Each log entry is a pair (timestamp, message). Two entries are duplicates when their message strings ar...
Design a Tunable Recurring-Transaction Detector
Design a Tunable Recurring-Transaction Detector You receive a file of transactions and need to identify likely recurring payments such as subscription...
Design a Stateful Working Hours Register
Design a working-hours register for employees who badge into and out of an office. Describe the data model, public operations, validation rules, and a...
Build a CSV-to-JSON Classification Service
Build a CSV-to-JSON Classification Service Build a backend service in stages. First, an HTTP request supplies a server-visible CSV path and the servic...
Implement Deterministic Merkle Hashing for a Repository
Implement Deterministic Merkle Hashing for a Repository You are given a repository abstraction with operations to identify files and directories, read...
Design a Rule Evaluation Engine for Spending Policy Violations
Design an extensible rule-evaluation engine for a corporate spending product. Employees submit expenses, and managers choose policies that flag expens...
Clarify and Design Social-Graph Milestones
Clarify and Design Social-Graph Milestones An interview exercise progresses through a social graph with snapshots, a milestone for retrieving follower...
Build a Three-Service Refund Workflow over HTTP
Build a Three-Service Refund Workflow over HTTP For this exercise, build three independently running local services: - Order Service owns order data a...
Design an Extensible Animal-Chess Game Engine
Design an Extensible Animal-Chess Game Engine Design an object-oriented engine for a two-player, turn-based animal-chess game. The interviewer will su...
Design a Space-Efficient Versioned Recipe Shopping Cart
Design a Space-Efficient Versioned Recipe Shopping Cart Design an in-memory shopping cart for a cooking app. Each recipe has an ID and a list of ingre...