[00:01] read replicas, but there are three more levers to scaling reads. The first is CDN caching. You can serve cacheable responses from edge servers that are You'd want to use this when your users are geographically distributed and you
[00:14] want to cut origin load times by 90% or more. Next are materialized views. You can precompute expensive queries and store those results as a table. You'll use this whenever the queries are really slow, but the underlying data changes
[00:27] rankings, leaderboards, or aggregate counts. Last is application level caching. You can store results directly in your app server's memory. This gives course it dies on restarts and it doesn't share across instances. Combined
[00:43] the playbook. Start with caching, add read replicas when your database is still struggling, push to the edge when latency matters, and precompute those queries that are too expensive to run live. Learn more at hellointerview.com.