Meta — LLD / Machine Coding Questions

45 unique questions from real interviews

#	Question	Editorial	Video
1	Design a Library Management System (5x)
2	Design a Multi-floor Parking Lot (5x)
3	Design a Feature Flag System (3x)
4	Design a Rate Limiter (3x)
5	Design a multithreaded job scheduler (2x)
6	Design a Ride Hailing App (2x)
7	Design a simplified version of Twitter with three core features (2x)
8	Design a Vending Machine Leasing System (2x)
9	Design a Circuit Breaker
10	Design a Coffee machine
11	Design a component that logs the state transitions of workflow steps
12	Design a concurrent hash map
13	Design a crawler for a hotel booking site
14	Design a Drop down menu
15	Design a FastAPI endpoint to return a paginated response given a query page
16	Feature flag (feature toggle) system
17	Design a Feature Toggle Service for an application (e
18	Design a Logger
19	Design a music player with the given features -
20	Design a payment gateway integration system supporting providers like PayU
21	Design a payment processing system that handles credit card transactions
22	Design a Resource Manager with operations like adding resources
23	Design a Ride matching Service
24	Design a Service Dependency Impact Analyzer
25	Design a service to find a rider for a quick commerce app-LLD
26	Design a service which talks to LLM
27	Design a Smart Elevator System
28	Design a stack using an array
29	Design a Survey system that can have multiple pages
30	Library / Parking Lot System
31	Design a system to calculate pricing for Uber Eats
32	Design a Task Scheduling System (like Cron/Airflow)
33	Design a ThreadPoolExecutor (similar to Java’s internal implementation)
34	Design a transaction processing system with the following components
35	Travel Booking Service (OOP)
36	Design an Airport Scheduler (single runway)
37	Design an in-memory file system that mimics basic Linux directory operations
38	In-memory inventory service
39	Design an offline download manager for a social media app
40	Design an order processing engine to handle multiple orders where one order
41	Design an Uber-like platform with multiple specific constraints and conditions
42	Design the classes and services for a Food Ordering system supporting search
43	Design the classes using Dependency Injection
44	Data access layer
45	Design the Snake & Ladders game