Interview questions

How to implement a queue using stack? ( not this question, but this type of questions and the question many be more difficult than this.)

Companies: Netflix

HTML Entity Parser

Parse a string and replace the predefined HTML entities (", ', &, >, <, &frasl;) with their corresponding characters. Ensure only exact entity tokens are…

General practice

Human Traffic of Stadium

Identify sequences of at least three rows with consecutive id values (ids consecutive, dates needn't be) where every people >= 100. Return all rows from…

General practice

I was asked a few behavioural and technical questions about my resume. Also a Leetcode Hard

Companies: Citadel

I was asked to implement a concurrent system component and then discuss how to make it fault-tolerant under specific failure modes. The follow-up questions were brutal—they kept pushing on edge cases regarding memory safety and race conditions in a high-throughput environment. It felt much more like a real-world engineering challenge than a standard whiteboard session.

I was asked to implement a concurrent system component and then discuss how to make it fault-tolerant under specific failure modes. The follow-up questions were…

Companies: Anthropic

i was given a medium leetcode case (Graph). i was also told that in the real interview, they usually give out medium to hard cases, most of them are graphs.

i was given a medium leetcode case (Graph). i was also told that in the real interview, they usually give out medium to hard cases…

Companies: Google

I won't break confidentiality here. One tip though: I think practicing Hackerank is a better way to prepare for Jane Street interviews than practicing Leetcode.

I won't break confidentiality here. One tip though: I think practicing Hackerank is a better way to prepare for Jane Street interviews than practicing Leetcode.

Companies: Jane Street

Identify the Largest Outlier in an Array

Given an integer array where exactly n-2 elements are "special", one of the other two elements equals the sum of those special elements and the…

General practice

Image Overlap

Given two n×n binary matrices, find the maximum number of positions with 1s in both matrices obtainable by translating (shifting) one matrix over the other…

General practice

Image Smoother

For each pixel in an m x n grayscale image, compute the floor of the average of the pixel and its up-to-8 neighbors (using only…

General practice

Immediate Food Delivery I

Given an orders table with order time and delivery time, write a SQL query to return orders that were delivered immediately after being placed (i.e.…

General practice

Immediate Food Delivery II

Compute the percentage (rounded to 2 decimal places) of customers whose first order—defined as the row with the earliest order_date per customer—was immediate…

General practice

Immediate Food Delivery III

Design a dynamic system that supports adding/removing delivery agents and assigning the best available agent to incoming orders in real time, optimizing for proximity or…

General practice

Immutability Helper

Implement an immutability-helper that, given a nested object/array and a spec of update commands (e.g., $set, $push, $unshift, $splice, $merge, $apply), returns a new data…

General practice

Implement a DFS for a matrix to find a certain value

Companies: TikTok

Implement a easy tree command

Companies: Airbnb

Implement a fibonacci tree to get nth value in tree

Companies: Databricks

Implement a GPU credit management system.

Companies: OpenAI

Implement a rate limiter using the sliding window log algorithm

Companies: LinkedIn

Implement a streaming database with the given constraints and requirements.

Companies: Anthropic

Implement a type of sort algorithm in Python

Companies: Anthropic

Implement an in-memory database in CodeSignal, with each round adding more functionality.

Companies: Anthropic