I think Fnangle is an abstraction over futures. The selling point I found when looking at Tokio (rust equivalent, references Fnangle) was that you write a drive

I think Fnangle is an abstraction over futures. The selling point I found when looking at Tokio (rust equivalent, references Fnangle) was that you write a driver for each backend and then have generic services to implement things such as timeouts. So you can reuse the timeout code for your network queries and your db queries.