🏗️ Machine Coding & System Design Insights

🟢 Game Systems (Snake & Ladder)

The Villain: "The God Class." Putting board logic, player logic, and dice logic into one giant file.

The Hero: "The Entity-Component Separation."

The Plot:

1. Board handles layout and jumps (Snakes/Ladders).
2. Game manages turns and win conditions.
3. Dice is a standalone utility.

The Twist: "The Infinite Loop." A snake leading to a ladder that leads back to the same snake.

🟡 Concurrency (Elevator System)

The Villain: "The Race Condition." Two people on different floors calling the same elevator, causing it to jitter.

The Hero: "The Request Queue & State Machine."

The Plot:

1. Collect all requests in a thread-safe queue.
2. Use a Strategy to decide which floor to visit next (SCAN algorithm).

The Twist: "The Starvation." The elevator keeps serving middle floors, leaving the top floor waiting forever.

🔴 Distributed Systems (Job Scheduler)

The Villain: "The Double Execution." Two workers picking up the same job from the DB simultaneously.

The Hero: "The Distributed Lock" (Redis/Zookeeper).

The Plot:

1. Use SETNX to claim a job ID.
2. Heartbeat to ensure the worker hasn't died.

The Twist: "The Zombie Job." A worker crashes without releasing the lock, blocking the job until it expires.