The way I typically think of it is • Model is “whatever you need to store persistently, how you represent that data, how should the data be structured and stor

The way I typically think of it is • Model is “whatever you need to store persistently, how you represent that data, how should the data be structured and stored when it’s at rest (eg in a database, nosql environment, or big data query system), how you are expected to query that data when you need it, mediates common CRUD data query operations on the store, and broadly handles giving back the results of any stored data query. Intent of the model is to be a black box the controller can talk to whenever it needs something from “storage”. If you did it right, you can change the entire underlying data store and endpoint, and as long as the API for the model is preserved, the controllers don’t even notice. • Controllers mediate “turning prepared or cached model data queries into something to give back to the user” and “listening for the user wanting to do something and responding appropriately by fetching needed model data or server resources”. Handles moving between pages, incoming API calls, last mile data filtration (where last mile is based on milliseconds to do it, >25ish or so and it probably belongs on the model) and cleanup if any is needed, and is first line of contact (and defense) for anything a user’s triggered. • Views are whatever the user can visibly interact with and see, and provide buttons, links and interactibles which hook into controller calls to change things or give back data I’ve found the above model typically has good separation of concerns, usually avoids most fights of “does this belong on the model or controller”, and you can usually cleanly parallelize work between multiple people on a small team if you use ~~waterfall~~ scrum to agree on a data model for each endpoint and needed functions before starting.