What it is
A demo on purpose. It exists to show what a full Kotlin stack looks like when every part of it is real rather than sketched — Compose Multiplatform clients for Android, iOS, desktop and the browser, a Ktor server that compiles both to the JVM and to a native Linux binary, and one shared module holding the API contract for all of them.
Live at mani.kotlin.website.
The parts worth copying
The same code on both sides of the wire. The same @Resource classes route requests on the server and build URLs on the client, so a renamed path moves both ends together — there is no place for a string on one side to disagree with a string on the other. The same code signs a token in the JVM build and in the native build.
The README screenshot is a golden. The image at the top of the repository is not a screenshot somebody committed; it is one of the files the screenshot tests compare against. Re-recording the goldens redraws it in the same commit, so it cannot quietly go stale — if the picture is old, the tests are red.
Two of its dependencies were written for it. mongkn, because the native server build has to talk to the same database as the JVM one and no official driver exists, and viddik for the goldens above.
What it is not
No email confirmation, no password recovery, no rate limiting, and passwords hashed with salted SHA-256 rather than a slow KDF. Saying so is the point: a demo that quietly omits the security work invites someone to copy it, and the omissions are exactly what a reader cannot see. The public instance is a playground.