How to Build Business Applications Leveraging a Domain Driven Architecture

Who are we?•Brian Anderson

• Founded OST project-based App Dev team (http://ostusa.com / @OSTgr)

• 15+ years business and software development consulting experience• Crowe Chizek• SageStone -> NuSoft - > RCM Technologies• OST

• Co-founder of Tourneytopia.com, PayItSquare.com and TourneyLogic.com

• Twitter: @brianmatic, Github: https://github.com/brianmatic

•Brian Scaturro• Consultant @OSTgr• Worked for OneUpWeb on the bay in Traverse City• Author of Paratest – https://github.com/brianium/paratest• Avid reader and open source developer• Twitter: @scaturr, Github: https://github.com/brianium

OST is headquartered right here in GR

Here we go

Developing greenfield apps is hard Most get locked into an architecture that doesn't scale and change becomes difficult and slow as the system grows.

Why does this happen so often?

Too many times application architects focus on the technical problems instead of designing for the problem domain.

“The most significant complexity of many applications is not technical. It is in the domain itself, the activity or business of the user" – Evans

Example Architecture

•Tiers •UI• Business •Data Access•Database

•Does this architecture represent the business?

•No…

How to do it right?

•Domain Driven Design•Focus on the domain model first.•What the heck is the domain model?• Official definition:

• A domain model in problem solving and software engineering is a conceptual model of all the topics related to a specific problem. It describes the various entities, their attributes, roles, and relationships, plus the constraints that govern the problem domain

•Let us just show you…

Let’s Model• Idea = Trello.mini• Wireframes• Domain Model

Onion Architecture

•The domain model is the core.•Build your architecture around it.

OST Open Source Contributions•nDriven• .Net-based•https://github.com/OSTUSA/ndriven

•nDriven CLI – command line interface for creating a nDriven boilerplate project.• https://github.com/OSTUSA/ndriven-cli

•Driven•PHP-based•https://github.com/OSTUSA/driven

Let’s code it• nDriven – Baseline Onion Architecture Project

• Setup a new project

• Develop the domain model• Look at how easy it is to interact with

• Make the domain model persist to a db in the Infrastructure layer• DB schema• Create a DB through a migration• Map models to DB• Leverage the Repository design pattern

• Finally, build the Presentation layer• Develop against the domain model• Use an MVC framework• Users expect modern client side interactions• It has to have a responsive design that works on all devices

Want our code?

•Reference sample application•OST Todo’s•https://github.com/OSTUSA/ost-todos•Great reference for• .Net MVC 4•Angular JS – Javascript MV-Whatever•Bootstrap•Built on nDrive

Q&AThank You