Thinking aloud: Query your one SQLite table for unchecked comments, send each to telegram/a single HTML page with ‘approve’ and ‘censor’ buttons. Auto-unapprove-and-uncheck comments with words from an editable list (NFT, Bitcoin, etc). Easy and would cater for most personal/hobby use cases.
It’s nothing to do with how well frequented your site is; any site that can be found by a web spider is going to get bot spam.
Of course you’re completely free to try it, and indeed it’s pointless to spend any more time debating it here. You really should just try it if you want to.
I guess what I’m saying is the reason most people find it best just to use a 3rd party platform is not because nobody can write “100 lines of code” to do it themselves, but because if they do that they experience the spam problem and just decide it’s not worth it. That was my experience.
That said, it may be easier to combat spam now with a classifier using an LLM or BERT.
A single SQLite3 table and a post, approve and delete end points would be about 100 lines of code and would cater for 90% of hobby/personal sites
Part of the reason the web is so soulless and drab is that people no longer have the skills to create simple functionality. I almost yearn for the days of PHP