Domain Modeling

with a fully working example

Modeling a Grocery List app

Modeling our system’s behavior

Using synchronous logic, then the infrastructure sandwich.

Polyglot guide

We will talk Domain-Driven Design, Hexagonal Architecture and probably a bit of Clean Architecture. Mostly in a function/data-oriented paradigm.

Pushing infrastructure/adapters to the edges

We will represent all the business before even mounting an in-memory or database repository.

What is domain and what is not?

Here is a simple decision tree: Is it a concept that can live outside your company?

Yes -> not domain
No -> domain

OOP, that traitor

To me, Object-Oriented Programming is a stale paradigm imported by the video game industry because it suited them there. This industry now uses the entity component system. In my opinion, it does not suit regular business projects.

I can endure the immutability performance overhead in exchange for predictability and peace of mind. The trade-off is easily made.

Yet, because OOP is such a major standard and TypeScript adoption is young (in comparison to other languages), there is not much documentation regarding how to model a system in TypeScript using functional/data-oriented programming.

That is the subject of this guide. How about we get started?