In the continuation from the previous post, here we look at how to do context mapping from sample real-world examples. In this post we look at how to model Customer Management from a customer support perspective and how Customer 360 would look like as a context map With this post, I hope to give you…More
DDD Context Mapping by example: Policy Management
DDD context mapping can be confusing without real-world examples. In this post we will model sample implementations for two scenarios using bounded context maps and learn to analyse the relationships from the maps. With this post, I hope to give you a fair idea of how to do apply DDD into build good distributed features…More
Single view of Customer from Distributed Software: Part I
Customers are at the heart of every business model and industry. It is therefore no surprise that throughout my journey as a consultant I have witnessed initiatives eventually lead to one trying to get a single, unified view of the customers at they appear in various IT systems The challenge is when technology implementations focus…More
Strategic DDD and Context Mapping for Architects
Conway’s law says the structure of our organisation guides how we build software and this holds specially true today as we build distributed software services rapidly and at scale. So how do we map business domains, technology services, engineering teams, communication patterns, dependencies as enterprise architects and integration domain architects? The problem 1. Growing disconnect…More
User Journey, User Story vs Domain Story: What’s the difference?
While running DDD workshops with clients, I have had this question come up several times – “What is the difference between a Domain story vs a User Story?” Here is a quick look at differences: User journey story: Is a technique for describing how the user interacts with our business (and business systems) over time…More
Understanding Error Handling in Integrated Solution: Making things robust
Integration engineering regardless of the architectural style (EAI, microservices, SOA, accident etc) must ensure the end solution is robust and reliable. These are two key attributes of any solution and rely on handling scenarios when things do not go exactly as planned when two systems talk to each other over a network Planning for unexpected…More
Software Monoliths
Companies need to modernize software and engineering to scale to reach new customers. Many find it increasingly hard to deliver outcomes safer and faster in a rapidly changing business ecosystem because of internal complexity from existing practices, systems and integrations. One cause is “shared” collaboration of resources between teams and in this post we explore these monoliths and monolithic practices More
Capturing the essence of your software with diagrams: Techniques for the engineer, designer and architect
Pictures are “worth a a thousand words” and in the software industry they can save time and help inspire the collective imagination A good picture about a software system at right level can convey the right details. It is about what you leave out as much as what you put in and structure – there…More
Asynchronous Communication Patterns: Not all events are the same
When integrating systems we often end-up writing asynchronous messaging interfaces for mostly system-to-system communications. This conversation technique is great because it does not require the sender and receiver to stay connected to each other in a session at the same instance in time, is non-blocking and you can make it reliable through message persistence, incremental…More
Domain Service Design and Patterns
Domain services implement core logic for a business domain and are a relied upon by experience and consumer services. Domain services can be self contained and store the business logic and state or rely on an external provider system (translating from a “raw system format” to a “canonical” domain format) In this post we look…More
Building strategic public and partner API experience: The power of experience adapter and an abstraction layer
As organisations look to take their offerings to the world outside for specific customers, partners or general public and grow their business, they must balance the risk of opening the door to internal mission-critical systems vs value provided. These offerings also must deliver the right experience, requiring an abstraction over the internal organisation services to…More
Salesforce Integration: Context and Patterns
Integrating with Salesforce be in a Marketing or Customer management context is the norm these days. Salesforce offers a lot of flexibility for information exchange, storage and for capturing events on change This post lists the interaction patterns we observe with Salesforce, the usage contexts, issues and best-practise Salesforce Inbound Patterns How do we create…More
How to build APIs with the right abstraction: SOAP, REST, ODATA
Leaky abstractions can be bad, especially in the context of APIs we expose to the world. Here are some thoughts on how to be less leaky and achieve more self-service with the APIs you build Modern software is built over the network with systems hooked-up either privately within the internal enterprise eco-system or with a…More
Common Service Caching Patterns
Caché implies to hide something. In a technology context this is “some service hides some data for a period of time (minutes to years)” A cache is a bit of information we stash away to better serve the clients using our service. Some of the questions cache implementers face are: Cache expiry and invalidation Mechanism…More
The difference between Open APIs and an Open API Specification
RESTful APIs can be internal (your company’s only) or public facing (Twitter). Thus internal APIs are called “Private APIs” and open to the public APIs are called “Open APIs” Now, while building an API accelerator for our clients I was asked by a well meaning colleague if this was an Open API; the intent was…More
Choosing the right tool for Stateful orchestration: Embedded Process Engines vs Serverless Step Functions
Just based on recent experience, I am going to put this out there – AWS Step Functions are great for technical state machines which move from one-activity to another but not really designed for stateful process orchestration and definitely not for implementing SAGA Serverless Step Functions from AWS or BPMN Engines? When building microservices, the…More
Single Entity, Multiple Master: Manage Complexity with Domain Services Integration Pattern
We often think of enterprise systems as the master systems for one or more enterprise data entities. We believe the lifecycle of the entity is contained and managed by users in a system in an encapsulated and convenient manner. However, there are scenarios where multiple systems master an entity and this is often because they…More
From Project to Product Teams: Implementing the Inverse Conway Move for better Software
Modern software engineering techniques within organisations deliver “distributed features” using agile techniques. These features are distributed across different systems and integrated to provide an end-to-end experience. Traditional project delivery brings in members from different system oriented teams to deliver these features in a loose and ad-hoc fashion and dis-bands the team after a project is…More
Domains, Sub-Domains and Bounded Contexts: Explained with example from industry
The Domain Driven Design (DDD) book and community use the language of Domains and Bounded Contexts. Often there is confusion around what is a Domain, Sub-Domain, Bounded Context and how do we tell the difference between one or other when we are in the trenches. This confusion can lead to poor design where our domain…More
Observations in building Domain oriented services: How to think about building the right service for your enterprise
APIs are the abstractions over technical services. Good APIs mirror strategic thinking in an organisation and lead to better customer experience by enabling high-degree of connectivity via secure mechanisms Too much focus is on writing protocols & semantics with the desire to design good APIs and too little on business objectives. Not enough questions are…More