13 Sep 2020
Unless you are not completely new to our profession I am pretty sure you already heard
about “Domain Driven Design” (DDD). But maybe you think that DDD requires quite some effort which is only worth it
in big software projects and that it has to be done in the beginning of a project to be effective?
This is not necessarily true …
Here is a book which nicely demonstrates that DDD and Functional Programming (F#) are two great tools to tackle
software complexity in any software project, even in a small pet project:
Domain Modeling Made Functional: Tackle Software Complexity with Domain-Driven Design and F#
08 Sep 2019
Yes, of course. Who has time? Who has time? But then if we never take time, how can we have time?
– Merovingian, Matrix Reloaded, 2003
If you think you don’t have time, even not to learn and practice, here is the one book you need
to take time for:
The Software Craftsman: Professionalism, Pragmatism, Pride
01 May 2019
It has been a while since my last post on “Implementing Clean Architecture”
but I wasn’t lazy ;-) In fact I was - apart from my day job - working on getting
Athena closer to the Clean Architecture. But there was one thing which puzzled me
for a while when implementing repositories:
In Clean Architecture
- all details are restricted to the frameworks layer. The database is a detail.
- all data conversion from the format most convenient for what ever persistence framework to the format
most convenient for entities and use cases, happens in the interface adapters layer.
How do I implement a repository in the interface adapter circle which accesses the TFS database using the
Microsoft TFS framework APIs? Isn’t that a violation to the Dependency Rule? In fact, isn’t any usage of a third party
API outside the frameworks circle a violation to the Dependency Rule?
In this post I am trying to answer this question.
03 Feb 2019
Accelerate: The Science of Lean Software and DevOps: Building and Scaling High Performing Technology Organizations
Do you work in one of the cool “Lean Startups” with “DevOp culture”? No? Me neither ;-)
As a software craftsman you know that DevOp practices like Continuous Delivery, modular architectures,
trunk based development, test automation, working in small batches and Continuous learning do make a HUGE DIFFERENCE
when it comes to software delivery performance!
If only you could convince management …
02 Feb 2019
Manage Your Day-to-Day: Build Your Routine, Find Your Focus, and Sharpen Your Creative Mind
This is one of these books which try to help you achieving more of what is important to you.
It is definitively not the first book I have read about “being more productive” and “focus”, but
“Manage Your Day-toDay” gave me a few new insights and reminded my of some things I had learn some time back already but
got forgotten in the chaos of daily business.
In fact I think every software craftsman should read regularly - at least once a year - about “focus” and “productivity”.
It is all too easy to get lost in these many and “important” things which pop up every day on our desks and in our email in-box.
Could you also spent your whole day sending and responding to email just to wonder what you have done the whole day in the evening?
18 Mar 2018
In the previous post I have discussed controllers and presenters.
I have shown you how I have implemented my controllers and presenters in the Athena project.
I was quite happy with my design so far but there was one thing which puzzled me …
In Asp.Net MVC a controller derives from
System.Web.Mvc.Controller which creates a dependency from my controller to the Asp.Net
framework. Taking the Dependency Rule strict that either means my design is invalid or my controller actually belongs to the
In order to learn what others think about this design I have posted my question at
and had a discussion with @herbertograca.
In this post I will share what I have learned and how I solved the puzzle …
01 Mar 2018
After having blogged with Jekyll for some while now I have found some convenient setup which makes me feel
quite effective. Today I want to share my setup with you. Maybe some aspects inspire you, maybe you want to
leave a comment about your own setup to inspire me?
20 Feb 2018
Last time we discussed about use cases and interactors and
stopped with the question: “Which role is than actually left to the controller and presenter?”
In this post I will take this question up and dive deeper into the world of controllers and presenters
in the context of the Clean Architecture.
18 Feb 2018
While preparing my next post on Implementing Clean Architecture I watched again
Uncle Bobs famous talk on Clean Architecture and Design.
I know it is more than three years old but if you are interested in Clean Architecture you should take your time and
watch it. Uncle Bob explains nicely - and a little bit funny as usual ;-) - what the Clean Architecture is about,
how the puzzle is built up and why it has to be like this.
And as a summary for this video and as an outlook to my next post here is the key message:
13 Feb 2018
Today I found a nice article on the NDepend Blog:
An Introduction To Clean Architecture.
The post gives a nice introduction by first motivating clean architecture by looking at the
short comings of the traditional layered approach. It then gives some history about the Clean Architecture.
Finally the post briefly introduces the Clean Architecture itself - the circles and the dependency rule.
It was a nice read - looking forward to read the follow-ups.
11 Feb 2018
Now that my architecture is screaming the business capabilities
of my system let’s look at those with more detail.
In the Clean Architecture all the application specific business rules go into the use cases circle.
But what is a use case? How big should it be? How does it interact with its environment?
04 Feb 2018
How do I make my architecture “scream”?
According to Uncle Bob an architecture “screams” when it clearly expresses its core business purpose.
The top level folder structure, the project/DLL names and the namespaces should express business aspects rather
than frameworks or other details.
Athena is a web application implemented in ASP.NET MVC. But is this important?
I could switch to Ruby on Rails or Node.js - it wouldn’t make any difference for the business.
Why do we let such details impact our project structure so often?
02 Feb 2018
Let’s briefly summarize what the Clean Architecture is …
31 Jan 2018
Did you enjoy reading Uncle Bob’s Clean Architecture?
I did! As with every book from Uncle Bob’s it is motivating and inspiring, right?
So let’s take his ideas and realize these in our projects to gain what he is promising!
But how do I start?
How do I transform an existing code base - following a layered (web) architecture - into the Clean Architecture?
28 Jan 2018
Are you scared of doing presentations? Especially in front of a bigger audience?
You don’t have to! Just don’t do these mistakes …
- Using corporate templates
- Having content packed slides
- Writing full sentences
- Focusing on the slides during presentation