So I am an independent software developer and I'm building up my portfolio in the hopes of helping with job applications. I have a broad design for a web based "app" (not really like a phone app, more like a web platform) that in reality would only "scale" if it used microservices. (It's a recommendation-based content engine, for hosting and linking to content and then recommending more content to users who participate voluntarily). The thing is, I would like to be able to run a version of this on a public VM, which is a thing I can afford, as a demo, and to host it on Github so people can do the same; I cannot afford to take the risk of using microservices "in the wild" and getting overrun with costs at this stage. But I also know that if I write the program as a local program that just queries against databases and the like, it will be something no one could really put into practice in a serious environment these days.
I know there are emulators for most functions of the big clouds, but most of them have licensing and practical/security restrictions against using them outside of your personal development machine.
So: is there a way to write an application that you could deploy on a Linux VM by itself, but with minimal modifications could be made to scale in a modern cloud environment? Or am I just aiming too far? (I'm sorry if this is vague in terms of technologies: I don't have a cloud preference for the application, and I'm not sure that the language etc. is relevant to answering this question, but I'm happy to elaborate or edit.)