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."
Find the Minimum Number of Meeting Rooms
Find the Minimum Number of Meeting Rooms You are given meeting intervals [start, end], where start < end. A room can host at most one meeting at a tim...
Implement an In-Memory Database
Implement a simple in-memory relational database that processes a sequence of tokenized commands. You are given commands: List[List[str]], where each ...
Implement a Stateful Trading Order Manager
Build a stateful trading order manager with deterministic command results, lifecycle transitions, bulk cancellation, and live-order display. Assign us...
Wildcard Dictionary Matching
This question evaluates a candidate's ability to design custom pattern-matching logic beyond simple substring or regex lookups, handling both fixed-le...
Minimum Path Length Through a Grid With One Allowed Cell Conversion
You are given an m x n grid grid where every cell holds either 1 (an open cell you may stand on) or 0 (a blocked cell). You start at the top-left cell...
Implement a FIFO Queue Using Two Stacks
Implement a FIFO Queue Using Two Stacks Implement a first-in-first-out (FIFO) queue using only two last-in-first-out (LIFO) stacks. The implemented qu...
Solve Four Online Assessment Coding Tasks
This set of four problems evaluates a candidate's proficiency in core algorithmic competencies including string parsing and bracket validation, bitwis...
Explain OS processes, threads, and memory
Explain OS processes, threads, and memory Explain core operating system concepts: processes vs threads, context switching, and scheduling (preemptive ...
Solve these string, subset, and date problems
You are asked to solve multiple coding tasks. 1) Reverse word order in a string - Input: a string s containing words separated by spaces (may contain ...
Solve Nearby Inventory and Word Segmentation Tasks
Two Algorithmic Tasks Implement both parts. They are independent and should have separate functions. Part A - Nearby Centers with Inventory An undirec...
Analyze time complexity for dictionary operations
Analyze the time complexity of the following dictionary/hash map operations. (a) Searching for a key: state average-case and worst-case time, and expl...
Solve three algorithmic tasks in Python
You are given 120 minutes to implement three independent algorithmic tasks in Python. Each task specifies the required input/output behavior, the cons...
Implement a Unique Lines Command
This question evaluates mastery of file I/O, streaming algorithms, stateful line processing, and memory-efficient handling of large inputs, situating ...
Implement a Distributed Rate Limiter
This question evaluates a candidate's ability to design and implement a distributed rate-limiting mechanism, testing knowledge of distributed systems,...
Solve the N-Queens problem
This question evaluates a candidate's competence in backtracking, constraint satisfaction, combinatorial search, recursion, and state representation. ...
Count the Ways to Decode a Numeric Cipher
A substitution cipher maps each uppercase English letter to a number: 'A' → 1, 'B' → 2, …, 'Z' → 26. To encode a word, every letter is replaced by its...
Most Frequent Call Stack from Profiler Samples
This question evaluates a candidate's ability to design an efficient hashing and frequency-counting solution over sequences, along with careful handli...
Validate a Shopping Cart
This question evaluates the ability to implement robust input and business-rule validation for shopping-cart items, including data integrity checks, i...
Code Editor with Block Shrink and Expand (Code Folding)
Implement the core of a code editor (similar to VS Code) that supports code folding: collapsing ("shrink") and restoring ("expand") indentation-based ...
Solve interval merge and string dedup problems
You are given three coding questions from a phone screen. Solve each independently. 1) Merge overlapping intervals Input: A list of intervals interval...