Options that I am aware of are Kitura
I have used Kitura myself and liked it a lot. I you want to have a flying start you could consider to bye this course: https://www.hackingwithswift.com/store/server-side-swift
I have no ties to HackingwithSwift but I highly recommend it.
Subject: [swift-users] Fwd: Swift for cloud
Greetings. I wonder if there where any attempts to use Swift for distributed applications/services, running within a commercial cloud, for both business intelligence, practical business domain DSL and UI/IX? And for mobile apps on iOS, of course. Same language - for any types of development. Including web(backend) development.
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