Coding & Algorithms Interview Questions
Practice 3,469 real Coding & Algorithms interview questions for 2026. Covers companies like Meta, Amazon, Google, Uber, and Microsoft. Real questions from actual interviews with detailed solutions — ideal for focused interview preparation. Coding & Algorithms interview questions are the single most common technical gate for software engineering roles and are used to evaluate problem framing, algorithm selection, complexity trade-offs, correctness, edge-case reasoning, and clear communication under time pressure. Expect this category to appear in early technical screens and repeatedly across onsite loops at companies that weight it heavily (notably Meta, Google, and Amazon). Interviews will test arrays and strings, trees and graphs, dynamic programming, hashing and two‑pointer techniques, and the candidate’s ability to test and optimize code in a shared editor. Prepare with timed mock interviews, practice in the same editor you’ll use live, and build a progressive schedule that moves from fundamentals to medium/hard problems; typical candidates invest several weeks to a few months of focused practice depending on seniority and target company.
"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."
Implement a size-bounded LRU cache
This question evaluates a candidate's ability to design and implement efficient data structures for capacity-bound caching, focusing on handling varia...
Map Weighted Random Draws to Indices
Map deterministic draws to weighted indices using cumulative ranges. Support large weights and many queries while preserving draw order and respecting...
Solve Refueling and JSON Parsing Tasks
This multipart question evaluates algorithmic problem-solving and parsing competencies, specifically resource-optimization and data-structure use for ...
Stream output until stop token appears
This question evaluates streaming string processing and pattern-matching skills, specifically handling token detection across chunk boundaries, bounda...
Find the longest palindromic substring
This question evaluates proficiency in string manipulation and algorithmic problem-solving, focusing on palindrome detection and substring handling wi...
Implement interval room counter and token manager
You are given two coding questions. 1) Minimum number of rooms for time intervals You are given a list of meetings, where each meeting is an interval ...
Determine allow/deny for an IP via CIDR rules
This question evaluates understanding of IPv4 addressing, CIDR range matching, rule ordering and precedence, and algorithmic correctness in determinin...
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...
Find first and last occurrence in sorted array
This question evaluates proficiency in array search algorithms and algorithmic reasoning, specifically the use of binary search techniques and careful...
Implement multi-head attention and LLM sampling
This question evaluates implementation and conceptual understanding of Transformer multi-head scaled dot-product attention and next-token sampling for...
Design hit counter for last 5 minutes
You are launching a new webpage and need a last-minute server-side metric to track popularity in real time. Implement a hit counter that supports the ...
Contrast processes and threads
What are the differences between processes and threads? Compare memory isolation, resource ownership, scheduling, context-switch cost, inter-process c...
Find minimum cycle cost per node
This question evaluates proficiency in graph algorithms and algorithmic optimization, specifically reasoning about weighted directed graphs, cycle cos...
How to settle multi-person debts in minimum transactions
This question evaluates algorithm design and combinatorial optimization skills, focusing on reasoning about net balances, transaction minimization, an...
Implement a web crawler using a provided API
This question evaluates understanding of web crawling mechanics, URL/hostname filtering, graph traversal concepts, and concurrent fetching, assessing ...
Decode a JWT string without libraries
This question evaluates understanding of JWT structure, Base64URL encoding, string manipulation, and JSON parsing as applied to decoding token compone...
Count changed nodes between two menu trees
This question evaluates algorithmic problem-solving with tree data structures, testing competencies in hierarchical diffing, node matching by sibling ...
Implement a versioned in-memory DB with CAS and history
In-Memory DB V2: TTL + Compare-And-Set/Delete + Historical Reads Implement an in-memory database keyed by (key, field) supporting TTL, conditional upd...
Implement a thread-safe money transfer
Problem: Implement a concurrent-safe transfer function You are given an in-memory store of bank accounts: - Each account has an accountId and a balanc...
Compute streaming sliding-window minimums
Problem You are given an integer array nums of length n and an integer window size k. You scan nums from left to right (streaming). At each index i, y...