The fundamental difference between a High-Level Blueprint (HLD) and a Low-Level Architecture (LLD) lies in their scope . An HLD provides a broader view of the solution, outlining the primary modules and their connections – it's essentially the "what" and "why." Conversely, an LLD digs into the sp

Caching Strategies Start With One Question: How Stale Can This Data Be? Most caching answers jump straight to Redis. The stronger answer starts one step earlier. Caching is a deliberate trade of freshness for speed, so the first thing to establish is how much staleness t