The two-part (so far) series of short detective novels by Malka Older has generally gotten attention for the romance and the detective work, and both of those are justified. But man does that praise overlook the SF worldbuilding here, which is fantastic.

This series is set in the distant future, after Earth has long become uninhabitable. Humans have colonized Jupiter (now called "Giant") by creating a series of platforms (shielded from the atmosphere) across the entire planet, connected by magnetic railways. I love everything about how the worldbuilding info is slowly doled out, with each visit to a new platform the opportune to learn more (rails instead of flight because flying through the atmosphere is tough and also the planet is huge; energy generally a non-issue since it's a literal gas giant; etc).

The goal of much of the settlement is to try to eventually make Earth habitable again. And that's the other part of the worldbuilding that I like a lot -- the university. Here, disciplines are divided into Classical, Modern, and Speculative. "Classical" now refers to anything from Earth, so Classical Geography is the department that studies the actual landmasses of the planet, partnering with Classical Biologists to try to determine where various species lived and how they interacted. Classical Literature includes "classics" but also stuff from our time, read with both literary intent and as a form of anthropology to understand pre-space society. "Modern" disciplines are the ones focused on the present day (so closest to the current concept of university), and "Speculative" ones focus on how they'll eventually repopulate Earth if the can.

Again, this is all doled out slowly, as is awareness of what tech is still available (space flight's an option, there's just nowhere to go), other attempts at colonies (Mossa was actually born on Io, which seems like it should be a much better colony option than Jupiter at first), etc.

And yes, these are also detective novels (both actually start as missing persons cases, though they soon become more sinister). Mossa, the "Sherlock," is on the planet's police force, while the Watson-like Pletiti is a scholar at the university. And yes, it's a romance (if you're the sort of reader who can't handle lesbians, this isn't your book), but it's a just some great SF with some nifty ideas on multiple fronts.

Oh, and there's even some libertarian content in the second book!

Older won the Prometheus Award (for best Libertarian SF) for Infomocracy, and while it's pretty obvious that neither she nor Mossa are libertarians themselves, she also clearly is open to a lot of their concerns. Mossa's refusal to go after a colony of libertarians who have essentially established a rogue platform in the second book (and I don't to dive more into detail, for plot reasons), in spite of what they're doing being both against the law and something she herself thinks is foolish, is something that stands out, especially given her own begrudging admission that they seem to be doing better than she thinks they should be.