Elevator System Design — Low Level Design Interview (LLD)

Elevator design is the hardest low level design (LLD) case study — the class model is easy, but the dispatch algorithm is where candidates separate. This is the full design plus the SCAN algorithm and cost function that land the offer. 🏢 Commonly asked at Uber, Google, and Amazon. You'll learn: • The core class model: Elevator, Controller, Request, Button • The SCAN (elevator) scheduling algorithm • The cost function for assigning requests to cars • How to handle multiple elevators and directions ⏱️ Chapters 0:00 Intro 0:16 Requirements 0:41 Entity Model 1:11 State Machine 1:41 Dispatch Algorithm 2:08 SCAN & Scheduling 2:42 Concurrency 3:07 Follow-ups 3:29 Interview Tips 📚 Part of the Low Level Design (LLD) Interview Prep full course. Subscribe for more LLD case studies: parking lot, LRU cache, vending machine, and more. 👨‍💻 ▶️ Full playlist:    • Low Level Design (LLD) Interview Preparati...   #ElevatorDesign #LowLevelDesign #LLD #SystemDesign #ObjectOrientedDesign #CodingInterview #Java #InterviewPrep #MachineCoding #FAANG