Interview Q&A / System Design
System Design interview questions
Caching, scaling, databases and classic design problems for beginners.
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- Can you give a simple example of when Layer 7 load balancing is necessary?
Layer 7 is needed when routing depends on request content, such as the URL path, headers or cookies. For example, sending /api traffic to API servers and /images traffic to a media cluster.
IntermediateQuick answer1 min read - How do polling, long polling, SSE and WebSockets differ for real-time updates?
Polling asks repeatedly; long polling holds each request open until there is news; SSE streams server-to-client over one HTTP connection; WebSockets give a two-way channel. Choose by direction of data and scale.
IntermediateQuick answer1 min read