Design Side - Client image optimization portfolio best practices?

I am building a portfolio website for a photographer, where the client will be able to upload his own photos and add them to his showcase. Naturally, the photos he will upload are most likely going to be high-res and larger file sizes. I’m worried about site speed and image optimization. Is there anything I need to do on my side to account for image optimization or loading speeds, or does Webflow’s image upload system already take care of that? Obviously I could also something like lazy-load, but was wondering if there was something I need to do in a general sense. Thanks!