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@kenny_baas
Towards Autonomous Aligned Teams
with Domain-Driven Design
Kenny Baas-Schwegler
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@kenny_baas
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@kenny_baas
“If the architecture of the system
and the architecture of the organization are at odds,
the architecture of the organization wins”
—Ruth Malan
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@kenny_baas
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@kenny_baas
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@kenny_baas
Any organization that designs a system
(defined more broadly here than just information systems)
will inevitably produce a design whose structure
is a copy of the organization's communication structure.
— Mel Conway
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@kenny_baas
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@kenny_baas
Label 1
Website
Label 2
Website
API
GATEWAY
Label 3
Website
Business 3
Business 2
Business 1 CRM
Datawarehouse
Data API
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@kenny_baas
[In our study at Thoughtworks we found] work
takes an order of magnitude longer when it
leaves a team.
— James Lewis (@boicy)
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@kenny_baas
“A loosely coupled software architecture
and org structure to match” is a key
predictor of:
1. Continuous Delivery Performance
2. Ability to scale org and increase
performance linearly
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Order Payment Packaging
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@kenny_baas
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@kenny_baas
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@kenny_baas
https://www.martinfowler.com/articles/microservices.html
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@kenny_baas
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@kenny_baas
To communicate effectively, the code must be based on the
same language used to write the requirements
- the same language that the developers speak
with each other and with domain experts
- Eric Evans
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@kenny_baas
https://www.huffingtonpost.co.uk/entry/american-tweets-about-great-british-bake-off_uk_61733eaee4b03072d6f6d012
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@kenny_baas
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@kenny_baas
We all know or should know that language is fluid, liquid, subject to the
whims of the people. Language evolves, as it should. Because language
changes to accommodate new users, the older users resist and complain.
http://tednellen.blogspot.com/2013/04/language-is-fluid.html
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@kenny_baas
It is not the domain experts knowledge
that goes to production, it is the
assumption of the developers
that goes to production
- Alberto Brandolini
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@kenny_baas
Instead of one canonical language,
create multiple bounded languages
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@kenny_baas
Business
Architects
Developers
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@kenny_baas
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@kenny_baas
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@kenny_baas
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@kenny_baas
A straight line between 2 points
corresponds to a compass direction in
reality..
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@kenny_baas
A straight line between 2 points corresponds to
a compass direction in reality..
• Except for points located in Greenland
• Except for points located in Africa
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@kenny_baas
A model is a simplified representation of a thing
or phenomenon that intentionally emphasizes
certain aspects while ignoring others.
Abstraction with a specific use in mind.
— Rebecca Wirfs-Brock
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@kenny_baas
Business
Architects
Developers
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@kenny_baas
Stop communicating business change
in system boundaries
(unit of deployment like in microservices, monolith)
Start communicating business change in
contextual boundaries that form the bounded context
(purpose, need, responsibility)
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@kenny_baas
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@kenny_baas
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@kenny_baas
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@kenny_baas
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@kenny_baas
Any organization that designs a system
(defined more broadly here than just information systems)
will inevitably produce a design whose structure
is a copy of the organization's communication structure.
— Mel Conway
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@kenny_baas
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@kenny_baas
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@kenny_baas
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@kenny_baas
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@kenny_baas
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@kenny_baas https://www.eventstorming.com/
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@kenny_baas https://www.eventstorming.com/
Mortgage
request
received
Mortgage
application
passed
Tender
signed
Declaration
rejected
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@kenny_baas
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@kenny_baas
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@kenny_baas
https://www.eventstorming.com/
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@kenny_baas
https://www.eventstorming.com/
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@kenny_baas
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@kenny_baas
What influences our grouping of the domains?
● Customers
● Resources
● People
● Team cognitive load
● Cohesion of change
● Change rate
● Culture
● Business strategy and their value streams
● Software architecture
● Organisation structure
● Knowledge & Practice
● …..
● Aka Contextual!
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@kenny_baas
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@kenny_baas
Using collaborative modelling to build a
shared understanding of your domain and use it to
guide your design _is_ the philosophy behind DDD
though. The rest is principles, patterns, and practices.
— Mathias Verraes
https://verraes.net/2021/09/what-is-domain-driven-design-ddd/
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@kenny_baas
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@kenny_baas
https://www.martinfowler.com/articles/microservices.html
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@kenny_baas
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@kenny_baas
Domain-Driven Design enables teams to have agency
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@kenny_baas
#CatTax
@kenny_baas
Baasie.com
xebia.com/blog/author/kbaas/
https://speakerdeck.com/baasie
Agile Alliance report:
https://www.agilealliance.org/resources/experience-reports/towards-auton
omous-aligned-teams-with-domain-driven-design/
https://virtualddd.com/