A customer wants a system that handles sudden spikes of ten times normal traffic and stays available across regions. How would you approach the design?

What the interviewer is looking for

• This question tests cloud & integration architecture. Designs scalable, resilient systems and integrations using queues, APIs, events and managed services appropriately.
• Strong answers: Autoscaling, queues or virtual waiting rooms to absorb bursts, caching and content delivery, stateless services, multi-region data strategy with its trade-offs, load testing, and cost balance.
• Likely follow-up: How would you handle data consistency across regions?

Another way it may be asked: A ticket-selling client gets huge rushes when big events go on sale. How would you design their system to cope and never go down?

A structure to follow: Frame, structure, analyse, recommend

1. Step 1

   Frame

   Restate the goal and ask what success is and what the constraints are.

2. Step 2

   Structure

   Split the problem into a few separate parts you can check one by one, and say what you will look at first and why.

3. Step 3

   Analyse

   Reason with the information you have, state your assumptions out loud, and say what data would change your mind.

4. Step 4

   Recommend

   Give a clear recommendation, the main risk, and the first step you would take.

This is guidance on shape, not a script. Use your own real experience and facts; never invent details to fill a gap. See the STAR guide and answer frameworks.

Common slips

• Listing ideas without choosing between them.
• Hiding assumptions instead of stating them.
• Finishing without a recommendation.

How to practise it

Answer in four spoken parts, one per step, then check you ended on a recommendation.

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