Unfortunately I agree with you Jane Street's tech blog and published lecture series are great and probably the best I know of. They make for great advertising to boot. Lecture series like Jane Street's are common in larger trading firms (more than 100-150 headcount) but I haven't seen one of JS' caliber yet.

If you welcome general corporate blogs, I think Google AI's technical blog is quite good. Their frequent publications on distributed computing strike a good balance of academic and practical ideas:

https://ai.googleblog.com

Cloudflare also has one of my favorite more engineering focused blogs.