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Caching and Performance Optimization Questions

Covers design and implementation of multi layer caching and end to end performance strategies for web and backend systems. Topics include client side techniques such as browser caching, service worker strategies, code splitting, and lazy loading for components images and data; edge and distribution techniques such as content delivery network design and caching of static assets; and server side and data layer caching using in memory stores such as Redis and Memcached, query result caching, and database caching patterns. Includes cache invalidation and coherence strategies such as time to live, least recently used eviction, cache aside, write through and write behind, and prevention of cache stampedes. Covers when to introduce caching and when not to, performance and consistency trade offs, connection pooling, monitoring and metrics, establishing performance budgets, and operational considerations such as cache warm up and invalidation during deploys. Also addresses higher level concerns including search engine optimization implications and server side rendering trade offs, and how performance decisions map to user experience and business metrics at senior levels.

EasyTechnical
0 practiced
Explain HTTP caching headers and revalidation mechanisms for web assets. In your answer, compare and contrast Cache-Control (including max-age and public/private), Expires, ETag, and Last-Modified/If-Modified-Since. Describe how these interact with browser caches, intermediate CDNs, and origin servers, and give one practical example of when you would use ETag vs explicit max-age.
EasyTechnical
0 practiced
Describe three clear scenarios where you would not introduce caching because the cost or risk outweighs the benefit. For each scenario explain the risks, consistency requirements, and alternative performance strategies you would recommend instead of caching.
HardTechnical
0 practiced
You need to convince a non-technical executive to fund a project to implement a multi-layer caching solution to reduce 99th percentile latency and improve conversions. Draft the outline of a pitch that includes the problem statement, measurable objectives, expected benefits, estimated costs, key risks, and a phased delivery plan with quick wins.
EasyTechnical
0 practiced
Explain how Service Workers can be used to improve client-side performance for Progressive Web Apps. Cover runtime caching, precaching, code-splitting interactions, and a simple strategy for offline-first behavior while keeping dynamic data reasonably fresh.
MediumTechnical
0 practiced
Explain the differences, pros, and cons between CDN caching of dynamic API responses at the edge and application-level caching (e.g., Redis) in the origin. For what kinds of content and use-cases would you use each, and when would you combine them?

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