I do not know Airtable too well, but n8n might have a connector for it. Then you could use the rest. good luck!

I am using appsmith for the app, with a pgsql db. Then n8n to query pgsql with its JSON functions and finally sending it to apitemplate.io to generate a PDF from the JSON and a template. The PDF then goes into nextcloud. With apitemplate you get 50 executions a month for free, which is enough for my use case. Hope this helps. (The use case is an equipment maintenance tool for the SCBAs of our fire brigade, where I need reporting for proving that maintenance was carried out)

I use restic with resticprofiles (one config file), notifications via (self hosted) ntfy.sh and wasabi as backend. Been very happy, runs reliably and has all the features of a modern backup solution, especially like the option to mount backups as if it were a filesystem with snapshots as folders, makes finding that one file easy without having to recover)