You’ve heard this before.

“Sir, table will be ready in 5 minutes.”

You smile.

You wait.

10 minutes.

20 minutes.

45 minutes later…

Host says:

Almost ready.

Still almost ready. 💀

So I turned this into a coding challenge.

And surprisingly…

This is a real system design problem.

🍽️ The Problem

The logic looks simple:

Add guests to a waitlist

Assign tables

Update status

Done.

Seems straightforward.

But real restaurants are chaos.

⚠️ What Goes Wrong?

In real systems:

• Tables take longer than expected

• Guests stay longer than predicted

• Wait estimates become wrong

• Queue order may not be fair

• Some people feel stuck forever

And suddenly:

👉 “5 minute wait” becomes 50 minutes.

Sound familiar?…