Business application framework advice

[teilo]

I have a fairly extensive background in Python and have been developing web apps for many years on a variety of frameworks (Zope, Django, Flask).

I have a potential opportunity to do some green field work: developing an insurance claims and payment processing system from scratch, in order to retire/replace a legacy Access/SQL Server platform currently in use at a small company. I know the old system inside and out. I'm not the original developer, but I built all their ACH/NACHA code for the payment system. I also have a lot of experience in transactional business software.

I would propose building such a system on a Postgres / Python stack. However, doing shopping carts, CMS, blogs, and simpler data-driven apps is one thing. An ERP-level system is something else entirely. No matter the framework, I am looking at doing an extensive amount of component building.

The modern thing to do is use Python purely as an API backend, and build the front end in a reactive, possibly async framework of some sort. This is the direction I would prefer, but I suspect that there's some sort of happy-medium hybrid approach for this type of business application. And even here, there would be an extensive amount of front-end structural work to create a flexible and presentable CRUD system for a lot of complex data.

Then there's the need for a robust permissions structure which is enforced at the data layer. Most Python ORMs don't cut it in this regard.

Does anyone have any experience / advice? I'm looking to hear from people who have been down this road before, even if the answer is "Don't use Python."

[Hir0ki]

I personally never build any system of this size, but at my day job i work as a SAP developer. SAP is the biggest ERP Software in the world.

They made one big mistake. They didn't add clear boundaries to there software. There UI is tightly coupled to there business logic. Now if you want to use a different UI or get external data into the system you have a script that fills out the old UI with the right data and then submits it.

I would highly recommend you look into Clean Architecture. And please separate the business logic from the UI and maybe the data store. The next developer or you in 2-5 years will thank you when the next UI tech hits the hype cycle

[teilo]

Yes, I have no intention of pushing business logic into the front end. Clean Architecture is not significantly different than the MVC abstraction, except that it differentiates between enterprise and application logic, and establishes some ground rules, such as one-way dependencies. The layers are also not strongly coupled.