I don't know the challenges of building a web-based Instagram, however I am a long-time user of Flickr, with which I manage a huge collection of personal photos.
The Flickr web interface definitely needs a modern browser (Chrome or the latest Firefox), otherwise it will choke from time to time, however that's to be expected when you're basically playing around with 10,000 photos. For me it does a spectacular job, more so than some native apps I tried (granted, I never tried Adobe Lightroom).
Thousands of images in a continuous virtual scrolling
window in HTML land? Slow.
You can use the same tricks you'd use in a native app, such as loading only the thumbnails that are currently visible in the user's window.
The Flickr web interface definitely needs a modern browser (Chrome or the latest Firefox), otherwise it will choke from time to time, however that's to be expected when you're basically playing around with 10,000 photos. For me it does a spectacular job, more so than some native apps I tried (granted, I never tried Adobe Lightroom).
You can use the same tricks you'd use in a native app, such as loading only the thumbnails that are currently visible in the user's window.