Where can I document things? If I put it on my person blog google won't find it - preferring instead SEO blogspam. If I document something but nobody reads it (including me), then the effort was wasted.
I recommend writing on your personal website! You will own your content and you can design the site and the user experience as you want.
Search is only one method through which someone can find what you write. I read a lot of personal websites that I found out about through friends, HN, and links from one site to another.
I put my stuff on my own website, despite my analytics saying I get next to no traffic. It's not a waste of time, because the largest benefit accrues to me when I write it. And if no-one reads it then hopefully I can avoid being over-pretentious while still having something to link folk to if any of my random thoughts ever become relevant.
Case in point: I'm not even going to link to it from this comment. It's easy enough to find for anyone who actually wants to find it :).
Codidact, Stack Overflow, or your own blog are all good options. In my experience plenty of problems are niche enough to rank highly in Google for the few people searching for them.
I'm a bit biased because my website has been around for a while and gets a fair amount of traffic. If you're going to create a digital garden, you better own the turf it's on. I have zero faith in other platforms treating its creators well.
I agree this is a challenge - Medium used to be okay for this as it could give you good reach, but I feel like it's become overly saturated with low-effort content lately.
Search is only one method through which someone can find what you write. I read a lot of personal websites that I found out about through friends, HN, and links from one site to another.