alt Hacker News> I now see relationships as their own domain rather than an attribute attached to a contact
I mostly skimmed this announcement, but this seems pretty obvious to me? Relationships form a graph, so it seems reasonable to use graph modeling techniques to handle them. At the least RDF triple style [1].
One thing I'd also strongly consider, in this age of LLMs, is how much you can store in text. A personal CRM seems like the kind of thing I want to check in to github, rather than deal with Postgres or even SQLite. And if you have a good structured text format (e.g. Markdown with YAML frontmatter, XML, json) then you can just point an agent at a repo and extract information that the app developer didn't even expect or add APIs for. Same for transformations. A full db engine is then more a performance optimization that can be applied for app-specific functionality.