Domain driven design microservices example

#Domain driven design microservices example software#
#Domain driven design microservices example code#

So CartCheckoutEvent, when generated by Cart, can be used by Payment bounded context in e-commerce to initiate payment from User.Дomain Events helps with building loosely coupled, scalable systems. They can be used as communication mechanism between different bounded contexts. Events like ProductAddedToCart, ProductRemovedFromCart, CartCheckedOut are important to business teams.Дomain Events can not be updated or deleted once they happen. LetвЂ™s take a example of Cart Entity in the Shopping cart bounded context. Now, letвЂ™s talk about some tactical patterns like Domain Event, Entity, Value object, Domain service and Aggregate.Дomain events indicate something important that has happened in the system from the perspective of the Business Team. How different bounded contexts communicate with each other and how they influence each other. More on that later (in this blog).Д¬ontext Map defines relationship between different bounded contexts. If your Business team is talking in terms of Database tables then as the Development Team you have influenced them incorrectly.Д«usiness and development team should communicate with each other using DDD tactical patterns like Domain Event, Domain Service, Entity, Value Object. It is a language which is spoken both by the Business Teams and the Development teams. Each bounded context has its own ubiquitous language.

Ubiquitous language applies withinВ bounded context. One bounded context typically has few (or one) micro-services

So bounded context is a linguistic boundary! Any time you see that the Product is acting differently, it is a clue that there are different bounded contexts in the play. So it is better to model different ProductВ class in each bounded context instead of having a common ProductВ class across bounded context. In Inventory Context Product is concerned about weight, expiry date, supplier, whereas in Shopping Cart bounded context, the expiry, the Supplier of the Product are not in picture. It is important to note that ProductВ in each bounded context has a very different behaviour. So we now have Inventory bounded context, Product Catalog bounded Context, and so onвЂ¦ We can use technics like event-stormingВ to identify such subdomains and bounded contexts. Inventory, Shopping Cart, Product Catalog, Fulfilment & Shipment and Payment. Bounded context helps in splitting e-commerce domain into smaller subdomains. LetвЂ™s talk about some strategic patterns like bounded context, ubiquitous language and context map.Д«uilding just one domain model for entire e-commerce will be very hard to comprehend and implement in the code.

#Domain driven design microservices example code#

If you want to see some code related to this, please do checkout: Everything in this Domain resolves around the вЂњProductвЂќbeing sold. We will use example of retail e-commerce domain to explain the following concepts. It was relevant in 2003 for designing modular monolith and today as well! Modular monolith is a topic for my other blog! The term was coined by Eric Evans in his seminal book вЂњ Domain-Driven Design: Tackling Complexity in the Heart of SoftwareвЂќ written in 2003 and was well ahead of its time! It started becoming very relevant with microservices architecture era.

#Domain driven design microservices example software#

It consists of collective wisdom from Software Industry, collection of patterns, principles and practices that will enable teams to focus on what is core to the success of the business while crafting software that manages complexity in both the technical and business spaces. If answers to any or many of such questions are yes, then Domain Driven Design is likely to be useful to your Team!Дomain-Driven Design is a language and domain-centric approach to software design for complex problem domains.

After discussion with team, we identified the desired system and sub-systems, their functions and created the boundary, meaning identified the bounded contexts using DDD traditional approach.Have you been finding it difficult to model boundaries of your systemвЂ™s microservices? Have you been slowed down by the Technical complexity of your codebase? Has your team been stepping on each otherвЂ™s toes ?.

We also identified core domain and other sub-domains, mapped these with their sub-functions in a rough diagram which we generally do in DDD to identify the boundary between context.

When you were noting down all the business functions/areas and sub-functions/areas, you were actually identifying the sub-domains (or in simple words the sub-system).

And, you involved business expert in all the discussion which is what we do in DDD and refer the business expert as the Domain expert, right?.

When you were understanding the business problem, you were actually analyzing the domain (or in simple words the complete System).

In fact, this article talks about Strategy phase of Domain driven design how let us see it again. Now, you are thinking where you have used domain driven design which is recommended approach.