Business Intelligence for developers

I'm a developer with apps backed with SQL databases. I want to give my CEO access through BI self-serving tools such as [PowerBI](https://powerbi.microsoft.com) or [Tableau](https://www.tableau.com/) . My issue is that the affordable tools all seem to require for someone to define the model in an interactive application leaving no means of automization. In practice, that means that every time I add some column somewhere I need to fire up some sluggish desktop application, manually add the column in the model there too and then trigger some deployment process. I'm a developer, I need to automate such things in order to not be overwhelmed with complexity. I've looked at PowerBI's file format, but it's binary. I've looked at both theses product's REST APIs, but all they allow is upload that binary and undocumented file format. I'm looking for - a way to create a model programmatically with these tools or - affordable alternatives that allow that. I'm otherwise satisfied with both these tools. I also had a look at [Looker](https://looker.com/) , but that already costs thousands of dollars per month.