To reduce database load and cut latency, caching is non-negotiable. Sen explains how to implement caches at multiple layers (Client, CDN, Application, and Database). He dives deep into eviction policies like LRU (Least Recently Used) and write policies such as Write-Through and Write-Back. Deconstructing Famous Architectures

Before touching microservices, Sen ensures his students understand TCP/UDP, Sockets, and Threading. His lesson on is arguably the most famous visualization on the internet for distributed sharding. He breaks down how DynamoDB and Cassandra distribute data without re-shuffling the entire cluster.

: What are the system's constraints? (e.g., "High availability is preferred over strict consistency; reads must be under 200ms.") Step 2: Capacity Estimation