2 months later, I finally decided to show it to the world by making a Product Hunt release.
I never thought it go viral on PH and HackerNews.
https://www.producthunt.com/posts/coolify
I fully spent the upcoming 3-4 days answering comments, feedbacks, and emails, and it was a pretty satisfying feeling.
When you know that you made something useful for a lot of people - but I think I do not need to explain this. If you ever had a small success, you know the feeling. :)
But the most satisfying things just came after. Companies started to contact me that they would like to pay for my product, even though it's free. What?
I quickly set up an Open Collective page (https://opencollective.com/coollabsio), so they can support my work financially.
It is an awesome feeling that my idea works.