How thumbnails are built
Goal: understand what happens to a photo between "uploaded" and "visible with a thumbnail," and where to watch that work happen.
The process queue
FrameCourier doesn't generate thumbnails (or apply watermarks, or embed metadata) inline while you
upload — that work is handed off to a background job runner called the process queue.
Every uploaded photo enqueues a thumbnail job; depending on the gallery and company
settings, it may also enqueue a watermark job and an exif job. Camera RAW
files enqueue a raw_extract job first, which produces a preview image before thumbnailing
can happen. Every upload also enqueues a job to move the file to cloud
storage.
Watching it run
While photos in a gallery are still processing, the photo grid polls for status every few seconds and swaps spinners for real thumbnails as jobs complete — you don't need to refresh the page.
To see every job across your account in real time — not just for one gallery — go to Queue in the sidebar. It shows counts of jobs currently processing, pending, and failed, and lets you retry or clear failed jobs.
How long does it take?
Jobs are processed automatically in the background. In practice a small upload's thumbnail is usually
ready within a minute or two; a very large batch upload can take longer since jobs are handled in turn.
Each job is retried automatically if it fails, and is only marked failed after repeated
unsuccessful attempts.