Architecture & LLD Preview
Elevator System
Design an elevator (or bank of elevators) with request scheduling, direction state, and door lifecycle.
A direction/door FSM driven by an injected scheduling policy (the LOOK algorithm): keep sweeping one way serving all requests, then reverse — far better than FIFO.
Core Design Challenge
"Design an elevator. Which floor does it serve next when several buttons are pressed at once?"
What You'll Learn:
- ✦Modeling system states and transition triggers
- ✦Encapsulating state machines into design patterns
- ✦Handling concurrency, thread-safety, and transaction isolation
- ✦Managing invalid actions and edge cases cleanly in code