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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.

HardBehavioral
29 practiced
Tell me about a time (or describe a hypothetical plan) when you introduced caching to reduce latency and cost. Walk through the decision process, stakeholders, performance metrics before/after, risks you considered, and how you validated the change and handled regressions.
MediumTechnical
29 practiced
Discuss strategies for caching results of complex SQL joins and filtered queries. Include cache key design to account for query parameters, invalidation via DB triggers or change-data-capture (CDC), and when to prefer materialized views versus an application cache.
MediumTechnical
27 practiced
You're preparing a pitch to execs to invest in a multi-layer caching platform to lower infra costs. Which metrics (technical and business) and cost-benefit arguments would you present, and what small pilot would you propose to demonstrate ROI?
MediumSystem Design
52 practiced
Design CDN caching rules for an application that serves static assets, public API responses, and authenticated user content. Include rules for cache keys, TTLs, cookie/header handling, origin shielding, TTL purging strategy and how to handle cache-busting for deploys.
HardTechnical
56 practiced
How should an SRE handle caching of sensitive data (PII) across servers and CDNs? Discuss encryption at-rest/in-transit, tokenization, TTL limitations, edge restrictions, role-based access, and audit controls to remain compliant.

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