Interview Questions
Practice the exact questions companies are asking right now.
"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."
"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."
"Legit the only resource you need. TC went from 180k -> 350k. Just memorize the top 50 for your target company and you're golden."
"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."
"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."
"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 a coffee ordering system
System Design: Coffee Ordering System Design a system for a coffee shop (or chain) that supports ordering drinks. Core use cases - Customer browses me...
Design a sandboxed cloud IDE
System design: Sandboxed cloud IDE (Colab-like) Design a multi-tenant, browser-based cloud IDE/notebook that lets users run code in an isolated sandbo...
Implement an in-memory database with TTL and backup
In-Memory Database (Levels 1–4: TTL and Backup/Restore) Implement an in-memory database that stores records identified by a string key. Each record co...
Design a single-node persistent in-memory cache
Scenario Design a single-machine cache used by a web service to handle read/write requests. The cache should: - Store key/value pairs in memory (fast ...
Compute ads revenue by geography in SQL
You have ad delivery logs for a shop-ads system. Tables ad_impressions - impression_id STRING (PK) - ts TIMESTAMP (UTC) - user_id STRING - shop_id STR...
Explain KV cache in Transformer inference
Question In Transformer-based language model inference, what is a key-value (KV) cache? Explain: - What gets cached (tensors, shapes at a high level) ...
Implement an in-memory SQL-like table
Problem Implement a simple in-memory database for one table. All values are strings. Each row is identified by a rowKey (string). Each row contains co...
Design a distributed crossword fill solver
Scenario You are building a service that fills a crossword-like grid with words. - The board size is not specified; assume a medium board around 50×50...
How to evaluate similar-listing notifications feature
Case study (Marketplace product analytics) Context: Circle is a US marketplace app for buying and selling second‑hand products. On a product listing p...
Design an ads audience targeting system
Problem Design an ads audience targeting system that allows advertisers to upload large user lists and then target (or exclude) those users when servi...
Implement credit ledger with out-of-order timestamps
Problem You are implementing a GPU credit ledger that supports adding credits, charging credits, and querying balances. Requests can arrive in any tim...
4.2 Design a Collaborative Document Editor
Real-time collaborative editing is one of those features that feels magical when it works — and absolutely nightmarish to build from scratch. Google D...
Design a RAG system with evaluation
Scenario You are asked to design a Retrieval-Augmented Generation (RAG) system that answers user questions using a private corpus (e.g., internal docs...
Compute probability an account is fake
A platform uses an automated classifier to flag potentially fake accounts. Assume: - Base rate: 2% of accounts are fake. - The classifier flags a fake...
Implement toy-language types and generic substitution
Problem: Toy Language Type System (Printing + Generic Resolution) You are implementing a small type system for a custom “Toy Language”. Types can be: ...
Design centralized log ingestion and query system
Problem Design a system to collect, transmit, store, and query application/data logs from many services/hosts into a central data center database. Req...
Design a fraud detection system
Scenario You are designing an end-to-end fraud detection system for an online platform (e.g., e-commerce marketplace, payments, account signup, or ad ...
Implement multi-level task manager APIs
You are implementing an in-memory task management system with a set of APIs that evolve over 4 levels. All APIs receive a timestamp: int parameter. Un...
Design a distributed web crawler
Problem Design a web crawler that starts from one or more seed URLs and continuously discovers and fetches pages. Requirements - Inputs: One or more s...
Simulate turn-based monster team battle
Design an object-oriented model and implement the core battle logic for a turn-based fight between two teams of monsters. The system should simulate t...