Using Lambda Calculus Models in Scala and Scala Web Frameworks

A lot of the research in my field was dealing with lambda calculus models. But every time I tried to implement prototypes or anything of what I was doing, it would be on quote unquote real programs. And then I was like, holy crap, when you build a real program, it's not one Lambda based function anymore. There's your database, there's your front end. You have your whole model of you controller. So who can see what in a system? This is like between two separate running programs, like separate projects. Well, so in my case, it was between different data values and a single program.