Full-page cache, catalogue output and browser work
Examine Theme CSS and Extension scripts separately. A global bundling or delay must be tested against product choice and checkout function.
Distinguish slow server responses from extensive theme/extension work in the browser. A warm full-page cache can provide a quick HTML retrieval, although variant selection or filters are slow to respond afterwards.
Where to check the setting in Magento
Compare cache hit and cache miss of the affected storefront page. After that, check the specific browsing work of galleries, filters and third-party scripts. A fast full-page cache does not automatically fix a sluggish interaction after loading.
Example of this specific finding
Illustrative control case: The visible title is waiting for a large stylesheet and a synchronous script in the head. A later loaded analysis script, on the other hand, does not cause this concrete standstill.
follow-up audit in Magento
Test comparable product and category pages under documented cache condition. Price, stock and personal content must not be obsolete or mixed by an optimization.
In the Performance Trace, check the critical resource and its dependencies. After a change, first test presentation, order, and interactions, then compare the load history.
Derogations and scope
CSS for the first visible area is often necessary. Not every blocking resource should be delayed or removed.
Reference: Magento Open Source or Adobe Commerce with classic storefront. Consider store views and extensions; other storefront architectures have their own configurations.
Classify the general error
Definition, system-independent causes and further correction examples: Prioritize blocking resources by visible effect