When it comes to performance, the first thing that comes to mind is Caching. The concept of Caching is complex to implement for a website, and we need to have the right balance with the underlying infrastructure. We need to understand the in-depth end-to-end data communications, their bandwidths, and how they get stored at each layer.
One general mistake development teams typically make is looking at code optimization randomly to solve all caching issues. While this helps resolve some performance bottlenecks and memory issues in legacy code, it does not eliminate the core problems.
The first and foremost fundamental point is that caching strategies differ between Static and Dynamic contents. Content Delivery Network serving contents is a no-brainer, and applications having a CDN make it easy to cache static contents for a specific amount of time on edge layers closest to the end-user.
CDN, however, makes it tricky to implement when it comes to semi-dynamic or dynamic pages. It is much easier to shift the caching responsibilities for the dynamic functionalities closer to the application layers.
The second tricky point is that, the Cache at the application layer influences the health of the underlying infrastructure. After any cache tweaks, it is always better to review the application server sizing after analyzing the cached data amount, cache size, cache duration, cache hit ratio, etc. Even caching at the database layer influences the underlying infrastructure. Query caches can be heavy and sometimes unnecessary, as all modern ORMs already have an internal cache implemented.
While it's tempting to resort to code optimization as a quick fix, the fundamental lesson learned is implementing caching tailored to the nature of content—static or dynamic. Also, the application layer involves a delicate balance, influencing the overall health of the underlying infrastructure. By approaching caching strategically and understanding its nuanced impact on the entire ecosystem, development teams can navigate performance challenges effectively and deliver a seamless experience to end users.