Coding & Algorithms Interview Questions
Practice 3,469 real coding and algorithms interview questions reported from interviews at Meta, Amazon, Google, Uber and Microsoft. The mix follows what these loops actually ask: arrays and strings, hash maps, two pointers and sliding windows, binary search, linked lists, trees and graphs, BFS and DFS, recursion and backtracking, dynamic programming, heaps and priority queues, and the occasional design-a-data-structure round. Roughly four in five are rated medium, which is where most technical screens sit; 477 are hard and cluster in onsite loops. 3,033 of them open in a console where you can run your solution against the test cases in Python, Java, C++ or JavaScript. 2,712 come from Software Engineer interviews, with the rest from Machine Learning Engineer, Data Scientist and Data Engineer loops, and 404 were set as take-home projects rather than live sessions.
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"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."
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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."
"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 longest increasing contiguous subarray
This question evaluates proficiency in array processing and algorithmic optimization, focusing on recognition of contiguous subarray properties and ha...
Compute array products excluding self and top-k
This question evaluates skills in array manipulation, in-place algorithm design, numerical stability and edge-case reasoning (such as handling multipl...
Solve linked list, string filtering, and puzzle
This multi-part question evaluates proficiency with linked-list pointer manipulation and constant-space linear-time algorithms, pattern-driven string ...
Design a weighted random value generator
This question evaluates understanding of weighted random sampling, probability-proportional selection, data structures for aggregating weights, and AP...
Find median of merged RLE arrays
The question evaluates understanding of run-length encoding, order-statistics (median) computation, and efficient merging of frequency-annotated seque...
Implement iterator merging lists with filtering
This question evaluates iterator/generator design, sequence merging, stateful filtering and deduplication, checking a candidate's ability to maintain ...
Find linked merchants by shared fields
This question evaluates the ability to model and detect entity linkages via exact field matching and weighted scoring as well as to reason about reach...
Implement lazy array and KV store
This question evaluates understanding of lazy evaluation and functional transformation chaining for a LazyArray alongside in-memory data structure des...
Check equal character frequencies
This question evaluates a candidate's understanding of character frequency analysis and algorithmic reasoning in string manipulation, measuring the ab...
Implement agent voting with average and sorting
Design an in-memory “agent voting” module that records ratings agents give to items (e.g., tickets/articles). Requirements: - Each vote is: (agentId, ...
Add two binary strings
This question evaluates proficiency with binary arithmetic and string manipulation, focusing on carry propagation and handling of very long inputs wit...
Compute minimum meeting rooms on circular day
This question evaluates a candidate's ability to reason about interval scheduling, circular time wrap-around, and resource allocation for overlapping ...
Generate all subsets (handle duplicates)
This question evaluates understanding of power-set generation and handling of duplicate elements, measuring competency in combinatorics, enumeration t...
Reconstruct original array from doubled shuffle
This question evaluates array manipulation, multiset/frequency reasoning, pairing logic, and careful handling of edge cases such as zeros and negative...
Solve Three OA Coding Tasks
This set of problems evaluates string and array manipulation, spatial placement and packing logic, and parity-based subarray counting within the Codin...
Calculate Per-User Usage Charges
This question evaluates algorithmic data aggregation, numeric billing computations, and the ability to model proration and threshold semantics across ...
Compute shortest path in cyclic graph
This question evaluates understanding of graph algorithms and shortest-path computation in weighted directed graphs, including handling cycles, non-ne...
Find missing ranges in interval
Given a sorted unique integer array nums and two integers lower and upper defining an inclusive interval [lower, upper], return all missing ranges not...
Implement a generic tree Node class
Design and implement a Node class for a mutable rooted tree. Requirements: store value, parent, and ordered children; support add_child, remove, move_...
Find shortest subarray to restore order
Given an integer array, find the shortest contiguous segment which, if sorted in ascending order, makes the entire array non-decreasing. Return the le...