Cloudflare scares me, they have way too much power. Maybe look for alternatives instead. Best case they are not from the USA, their demand for privacy and security is going down the drain faster than you can blink.

No special process, I installed Memories as admin on my Nextcloud, pointed it to my Picture-folder and my Smartphone-Uploadfolder, and made sure I had the other Apps as recommended here installed (e.g. ‘Photos’ to use albums and ‘Recognize’ for automatic face tagging)

The Memories-App on the Smartphone is also neat. And it is available on F-Droid.

My picture folder contains 1,4 TB of data, with many RAW-files and some Videos. Memories is handling that without a problem. I especially like the way it handles RAW-files, by grouping them together with the fitting JPEG.

I don’t know about how ressource heavy it is, but my server is really nothing special.

Features I like and use:

• automatic and manual people recognition
• sorting it on a map according to the geo data
• most used: Timeline, sorted by date. I barely organize my photos in folders now, because the timeline-sorting is what I want and enjoy.
• Albums to share fotos with family and friends. They don’t need a Nextcloud-Account to access them.

If you already use Nextcloud, try the Memorie-Extension. It has all the features of Immich. The tagging-feature for faces has been there for at least the year I am using it now.