Finally! So a few years ago when I read All the Birds in the Sky I struggled to figure out what it was, and I still don't know, but now I feel like I know what to recommend to people who loved it.
Anyway, This Is How You Lose the Time War is about a surprising relationship that develops between 2 deadly operatives in a possibly neverending war between the forces of nature and the forces of technology. It's a war that rages through time--literally they time travel all over the place--across universes, and into and out of history. It's amazing and lyrical and really strange.
I hesitate to recommend it to sci fi readers because it's kind of a love story, and that's not something I normally associate with sci fi. I think if you like to feel unbalanced when you are reading, but totally sucked in to amazing prose, you will love it. If you like to know what's going on, probably not so much. If you want to master the art of letter writing, maybe.
The audiobook is very capably performed by Cynthia Farrell and Emily Woo Zeller.