Sure, the implementation is simple on day 0/1/7/15/365. Depending on the project, eventually it may not be, and you'll regret not better defining the functional

Sure, the implementation is simple on day 0/1/7/15/365. Depending on the project, eventually it may not be, and you'll regret not better defining the functionality. Again, it's not that every single piece of code in your repo needs an interface, just large components, like data stores.