Software Engineer Interview Questions
Practice 4,229 real Software Engineer interview questions for 2026 — real questions from actual interviews with detailed solutions to speed your interview preparation. This collection reflects what top tech firms like Meta, Amazon, Google, DoorDash, and TikTok typically evaluate: rigorous coding and algorithmic problem solving, increasing expectations for end-to-end system design (including GenAI/LLM design at some teams), clear complexity analysis, and reliable engineering judgment under constraints. Expect a multi-stage pipeline: recruiter screen, timed or asynchronous coding assessments, one-to-more live coding rounds focused on data structures and correctness, system-design conversations for mid and senior levels, and behavioral/hiring-manager interviews that probe ownership and collaboration. To prepare, prioritize patterned practice (timed mock interviews and implementation + optimization), learn scalable design frameworks, rehearse concise trade-off communication, and tailor examples to company signals like Amazon’s leadership lens or product/latency focus at delivery and media-driven teams. Consistent, feedback-driven practice that combines problem-solving speed, clean code, and measured design reasoning is the quickest path to offers.
"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 access control system (RBAC + resource-based)
Design an authorization system that supports both: - Role-Based Access Control (RBAC): users/groups have roles (e.g., Admin, Editor, Viewer) that gran...
Build span trees from unordered trace spans
You are given an unordered list of span objects. Each span is a map/dictionary containing at least: - span_id (string, unique) - parent_id (string or ...
Find smallest permutation under constraints
Given a non-negative integer n, consider its decimal digits as a multiset (digits can repeat). 1) Return the smallest possible integer that can be for...
Find cheapest common ancestor in a tree
Coding You are given a rooted tree where each node has: - an integer price - a pointer to its parent (root has parent = null) - a list of children Giv...
Design a device owner lookup service
Scenario Your server receives a stream of events from clients. Each event contains: - user_id - device_id - timestamp (event time) A device may be ass...
Detect cycles and break them in pod dependencies
You are given dependencies between software pods. Each dependency is a directed edge u -> v meaning pod u must be built/installed before pod v. Part 1...
Describe disagreement with leadership and your approach
Give an example where you disagreed with a leader (your manager, a VP, CTO, etc.). - What was the disagreement about (technical direction, priorities,...
Deep-dive a cross-team technical project you led
Pick one technically challenging project that required cross-team collaboration. Be prepared to go deep on: - Your role and what you personally owned ...
Design content moderation for a posting app
Scenario You are given a small demo “post creation” web app similar to a social network composer: - Frontend: a page where users type a post and submi...
Group duplicate files by content
Problem You are given a list of files in a filesystem. Each file has: - a full path (string) - a file size in bytes (integer) - file contents (concept...
Measure 45 minutes with two ropes
You have two ropes. Each rope takes exactly 60 minutes to burn completely, but each rope burns at a non-uniform rate (some parts burn faster than othe...
Minimize run-length encoded length with deletions
Problem You are given a string s (uppercase English letters) and an integer k. You may delete at most k characters from s. After deletions, you compre...
Design automated regression tests for an API
Scenario A team is launching a new RESTful API (or a new version of an existing API). You are responsible for designing an automated regression test s...
Determine allow/deny for an IP via CIDR rules
Problem You are implementing a simple IPv4 firewall. You are given an ordered list of rules. Each rule has: - an action: either ALLOW or DENY - a CIDR...
Simulate sticky load balancer with shutdown
Problem Implement a simulator for a load balancer that routes long-lived WebSocket connections across m backend servers. You receive a sequence of tex...
Parse nested XML inside CDATA
You receive messages in XML. One element contains a CDATA section, but the CDATA text itself is another XML fragment (i.e., “XML embedded as text”). E...
Compute triangle min path and dice stopping stats
You are given two independent interview questions. 1) Triangle minimum path sum (DP) Given a triangular array triangle with n rows, find the minimum p...
Describe your most challenging project and leadership
Describe the most challenging project you have worked on. Your interviewer will drill into details such as: - What the project goal and constraints we...
Navigate conflict, difficult people, and culture issues
Answer the following behavioral questions with clear examples (preferably using the STAR method: Situation, Task, Action, Result). Be explicit about y...
Compare WebSocket, SSE, and long polling
You are building real-time features for a web application and the interviewer probes your networking fundamentals across several layers of the stack. ...