The fundamental separation between a Architectural Plan (HLD) and a Low-Level Plan (LLD) lies in their breadth . An HLD provides a high-level overview of the solution, outlining the key modules and their interactions – it's essentially the "what" and "why." Conversely, an LLD goes into the precis

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