IPv4 addresses

Yes! This bothers me as well!

The last team I worked with did a lot with addresses and we used Go, and way too many of my coworkers were confused when the standard library used a 4-byte array to represent IP addresses instead of a string. I've even had to read IP addresses in hex (e.g. in raw packet dumps), so I'm used to counting octet offsets.

ULID

Ew, that violates much of the point of an ID, which should be entirely opaque. One of the best parts about a UUID is that it can be exposed to the user without fear of providing any data to an attacker (we use UUIDv4 for that reason).

But maybe it's useful for distributed systems where you trust the machines providing the IDs to have accurate timestamps, but then why not just use a tuple of a random ID and a timestamp? That way you can pick if you want lexicographical sorting or random distribution by swapping the parts of the tuple, and you can use standard 64-bit timestamps (and why milliseconds? Every time system I've used uses nanoseconds or seconds, only JS does the silly ms thing; maybe Windows does?). I guess compatibility with UUID is useful kinda, but I honestly don't see a ton of value here (saves you a column in the DB and an import I guess).

So to me, this seems like it's going to be misused a ton. I'm really scratching my head over using base32, because that's only useful for preventing transcription errors, which means it's intended to be seen and used.

I hope I'm missing something because this seems like an obvious "don't do this" situation.