FrontendHaltPerformance·Intermediate·Conceptual·1 min read
What does an image CDN do for you?
Short interview answer
From one high-quality source file it negotiates format based on Accept headers, resizes to requested dimensions, applies compression, and caches each variant at the edge. It replaces a build-time matrix of pre-generated sizes and formats with on-demand transformation.
Key takeaway
Explain the underlying mental model clearly, then support it with a concrete example and its trade-offs.