WebP optimization moved from a site task into an Engine build feature

Situation

On small marketing sites, a handful of oversized JPEG or PNG files can account for much of the LCP cost. Optimizing them manually once is easy, but the next uploaded image can immediately bring the problem back. Repeating the same manual fix across several sites was a sign that the platform itself was missing a capability.

Approach

A portable Sharp-based image runtime was added to the Engine build. The pipeline generates responsive WebP variants, rewrites HTML and CSS references, produces a manifest and is available by default to starter sites. The archive self-test also verifies that image optimization works from the vendored Engine package, not only from the Engine repository.

Outcome

Image optimization became a reproducible build step rather than one-off cleanup, just like HTML generation. New sites and sites upgraded to the Engine receive the same implementation, making performance improvements much more durable.