[hidro]

I have a full time software engineer job, and I work on a side project which is a HN Android app.

If your side project is a freelance one, you're probably in for a tough time, due to external pressure.

If your side project is a hobby one, my advice is to start small, and plan subsequent iterations small as well, so you can usually finish in say within a weekend. Anything bigger will make you feel overwhelmed. Also be prepared to sacrifice some personal time for your project, it's a hobby anyway.

I'm assuming that your side project has little in common with your main job, otherwise there is no fun in doing it. If that's the case, I find it especially useful if the side project can, in a way, contribute to the main project. E.g. you experiment things you want to learn with side project, and apply it into your main project some time in the future. This way you have a good cycle and motivation to keep innovating/experimenting. Making your code/project public so others can use/contribute is also a good motivation to keep it up.