How to understand when to apply optimizations? Have you ever had cases where you needed to solve performance issues?

Optimizations should be applied when there are real performance issues that affect user experience or system resources. Signs of the need for optimization:

• Long page load times or interface response delays.
• High CPU or memory usage.
• Frequent delays or freezes.
• Poor metrics in monitoring tools (e.g., Lighthouse).

In my practice, there have been cases where pages with many images and scripts loaded too slowly. We applied lazy loading for images, reduced bundle sizes, and optimized component rendering, which significantly improved speed and responsiveness.

It is important to first measure and analyze bottlenecks rather than optimizing everything indiscriminately, to avoid wasting time and worsening code maintainability.