Basic Framework
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System Design Card 432 — CDN and Media Delivery / Assess

CDN And Media Delivery — BASIC step map

Concern

Static and media-heavy workloads often need edge distribution rather than central-origin delivery for acceptable performance. Image-serving, file download, and streaming content systems depend heavily on caching at the edge.

Your first instinct is usually close — but not close enough.

What Assess means for this concern

In BASIC, the Assess step is where you identify the main architectural pressures and choose which trade-offs are actually important. For CDN and Media Delivery, that means the candidate should make this concern visible at the right moment instead of bolting it on at the end.

Design move

A good move is to compare plausible approaches before committing. Tie the concern back to the user flow, the workload, and the dominant trade-off. That keeps the design grounded and makes it easier for the interviewer to follow why a cache, queue, replica, partition, or rate limiter is actually necessary.

Common miss

The miss is treating global content delivery like ordinary API traffic. BASIC helps because the staged flow keeps this concern proportional to the prompt and connected to the rest of the architecture.

BASIC prompt

“When I reach the Assess stage, how does CDN and Media Delivery change the architecture, the trade-offs, or the review checklist?”

The real skill here
Assessment is comparison, not selection. Strong candidates explore at least two paths before committing. They don't just say 'I'll use a hash map' — they explain why the alternative (sorting, brute force, different data structure) is worse for this specific problem. That comparison is the signal.

References

S9 S14 S15

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