My current plan is to use the haxe programming language to create my kajam entry. In theory I can write a single codebase that can be compiled down to a headless (no graphics) server to run in the cloud, while having that same code be able to produce the playable version of the game. In order to get multiplayer support in the browser, I'll also be using websockets.
But more importantly I want to be able to quickly iterate on my entry during my free time, so I've set out to automate as much of the build and deployment workflow as possible. Nothing fancy, just a makefile that builds the server, deploys it to the remote server and launches it. I can then launch the client on my local machine and see messages passing between the server and client, which seems like a pretty important precursor to a remote multiplayer game. Testing with a local server on your development machine is OK but bypasses a lot of the issues that can occur with a 'real' server out on the interweb.
The test was successful but revealed that terminating the server on the remote server left a zombie process sitting on port 8000, which means that attempting to run the server again would fail as the port was unavailable. This behaviour didn't occur when hosting the server locally, so there's some instant proof that it's worth testing on as realistic a setup as possible. Hooray.