#dddesign — Public Fediverse posts

It has been quite an odyssey, but now it is finally here. Let me introduce you to:

📣 📚 Domain-Driven Transformation: Modernize Legacy Systems and Mitigate Risk 📚 📣

In this book, Carola Lilienthal and I present our approach to transform architecturally eroded systems at the strategic, tactical, and team-organizational level.

https://domain-driven-transformation.com/

#DDDesign #SoftwareArchitecture #LegacyModernization

Next Wednesday, October 15, starting at 18:45 we’re holding the #Meetup "TDD & DDD From The Ground Up by @ChrisSimonAu at N26's office.

Check out more information and confirm your attendance at:
https://www.meetup.com/dddbcn/events/311446227/

#DDD #DDDesign #DomainDrivenDesign #DDDBCN #TDD #TestDrivenDevelopment

ICYMI: I wrote about how your domains and bounded contexts don't map 1 on 1. #DDDesign
https://verraes.net/2025/08/domain-and-bounded-contexts-dont-map-one-on-one/

https://zalas.pl/object-oriented-event-sourcing/

#ddd #dddesign #eventsourcing #kotlin

https://zalas.pl/deriving-state-from-events/

#ddd #dddesign #eventsourcing #kotlin

https://zalas.pl/functional-event-sourcing-example-in-kotlin/

#ddd #dddesign #eventsourcing #kotlin

https://zalas.pl/functional-event-sourcing/

#ddd #dddesign #eventsourcing #kotlin

https://zalas.pl/functional-domain-model/ #ddd #dddesign #eventsourcing

Final (at least for now) batch of articles are now migrated from dev.to to my personal domain.

These are from my well received event sourcing series: https://zalas.pl/series/event-sourcing/

#eventsourcing #ddd #dddesign #kotlin

Next Tuesday, March 11, starting at 18:00 we’re holding the #Meetup "Optimizing for Flow & Evolutionary Design" at N26's office.

Check out more information and confirm your attendance at:
https://www.meetup.com/dddbcn/events/306576690/

#DDD #DDDesign #DomainDrivenDesign #DDDBCN #EventStorming #BoundedContext #Subdomain #CollaborativeModeling #CollaborativeModelling #DomainModeling #DomainModelling #DomainDiscovery #XP #ExtremeProgramming #Agile #TeamTopologies #DevOps

I did it ... I ported the 3-part aricle series

"Implementing Domain-Driven Design and Hexagonal Architecture with Go"

from Medium to Substack, where it's not paywalled.

https://eventsandstuff.substack.com/p/implementing-domain-driven-design-introduction

https://eventsandstuff.substack.com/p/implementing-domain-driven-design-domain

https://eventsandstuff.substack.com/p/implementing-domain-driven-design-hexagonal

#golang #go #dddesign #ddd #domaindrivendesign #hexagonalarchitecture #portsandadapters

Reposts very much appreciated! :-)

Hey folks!
I‘m looking for new professional opportunities from February 25 on!
If your org is hiring or you have recommendations … shoot me a message, please! 🙂

#dddesign #golang #hexagonal #eventsourcing #cqrs #eventdriven #tdd

Reposts very much appreciated! 💛

October was a busy month… for great reasons! 💪

It’s been rewarding to help organizations improve adaptability and service robustness, and I saw plenty of 💡 moments. Applying Domain-Driven Design and Chaos Engineering inspired fresh perspectives. And folks asked great questions.

Are you facing similar challenges? Let’s connect or visit https://joaorosa.consulting 🌐

#adaptive #organization #DDDesign #RobustSoftware #chaosengineering

October was a busy month… for great reasons! 💪

It’s been rewarding to help organizations improve adaptability and service robustness, and I saw plenty of 💡 moments. Applying Domain-Driven Design and Chaos Engineering inspired fresh perspectives. And folks asked great questions.

Are you facing similar challenges? Let’s connect or visit https://joaorosa.consulting 🌐

#adaptive #organization #DDDesign #RobustSoftware #chaosengineering

October was a busy month… for great reasons! 💪

It’s been rewarding to help organizations improve adaptability and service robustness, and I saw plenty of 💡 moments. Applying Domain-Driven Design and Chaos Engineering inspired fresh perspectives. And folks asked great questions.

Are you facing similar challenges? Let’s connect or visit https://joaorosa.consulting 🌐

#adaptive #organization #DDDesign #RobustSoftware #chaosengineering

October was a busy month… for great reasons! 💪

It’s been rewarding to help organizations improve adaptability and service robustness, and I saw plenty of 💡 moments. Applying Domain-Driven Design and Chaos Engineering inspired fresh perspectives. And folks asked great questions.

Are you facing similar challenges? Let’s connect or visit https://joaorosa.consulting 🌐

#adaptive #organization #DDDesign #RobustSoftware #chaosengineering

October was a busy month… for great reasons! 💪

It’s been rewarding to help organizations improve adaptability and service robustness, and I saw plenty of 💡 moments. Applying Domain-Driven Design and Chaos Engineering inspired fresh perspectives. And folks asked great questions.

Are you facing similar challenges? Let’s connect or visit https://joaorosa.consulting 🌐

#adaptive #organization #DDDesign #RobustSoftware #chaosengineering

Excited to head to Berlin this afternoon for my first #KanDDDinsky! Looking forward to an agenda packed with great talks and hands-on sessions about #DDDesign

Excited to head to Berlin this afternoon for my first #KanDDDinsky! Looking forward to an agenda packed with great talks and hands-on sessions about #DDDesign

Excited to head to Berlin this afternoon for my first #KanDDDinsky! Looking forward to an agenda packed with great talks and hands-on sessions about #DDDesign

Excited to head to Berlin this afternoon for my first #KanDDDinsky! Looking forward to an agenda packed with great talks and hands-on sessions about #DDDesign

Excited to head to Berlin this afternoon for my first #KanDDDinsky! Looking forward to an agenda packed with great talks and hands-on sessions about #DDDesign

I'm searching for a new professional opportunity from February on, an earlier start is possible but I'm not in a rush!
I bring along 25+ years of experience as a software developer, architect, team lead, learning designer (trainer).

Please share! :-)

Some of my skills and interests:
#golang #dddesign #hexagonal #portsandadapters #collaboration #agile #eventsourcing #cqrs

Our next DDD London meetup has been scheduled.

On Tuesday 19th November, Tim Mortimer will be talking about Executable Specifications.

See you there.

#dddLondon #ddDesign #domainDrivenDesign #bdd

https://www.meetup.com/dddlondon/events/303976744/

Our next DDD London meetup has been scheduled.

On Tuesday 19th November, Tim Mortimer will be talking about Executable Specifications.

See you there.

#dddLondon #ddDesign #domainDrivenDesign #bdd

https://www.meetup.com/dddlondon/events/303976744/

Our next DDD London meetup has been scheduled.

On Tuesday 19th November, Tim Mortimer will be talking about Executable Specifications.

See you there.

#dddLondon #ddDesign #domainDrivenDesign #bdd

https://www.meetup.com/dddlondon/events/303976744/

Our next DDD London meetup has been scheduled.

On Tuesday 19th November, Tim Mortimer will be talking about Executable Specifications.

See you there.

#dddLondon #ddDesign #domainDrivenDesign #bdd

https://www.meetup.com/dddlondon/events/303976744/

Our next DDD London meetup has been scheduled.

On Tuesday 19th November, Tim Mortimer will be talking about Executable Specifications.

See you there.

#dddLondon #ddDesign #domainDrivenDesign #bdd

https://www.meetup.com/dddlondon/events/303976744/

Architecture modernization anti-pattern: accessing another subdomain's data from the legacy system*

When building something new outside the legacy, you might be tempted to go direct to the legacy system to read/write data that you require (via the DB, CDC, or EDA).

If that data does not conceptually belong to the subdomain that is accessing it, you are breaking encapsulation: you are going via the backdoor to access another subdomain's data

1/3

#architectureModernization #ddDesign

Sometimes it’s best not to overdo the "DDD" when shaping the boundaries in your software architecture.

Using techniques like EventStorming you might achieve a clear conceptual model with well defined subdomains that domain experts agree with.

But it’s also important to analyse data flows: What information does a subdomain need from other subdomains to apply rules and make decisions?

Recently I hit this scenario...

1/2

**#ddDesign #ddd #swArch #eda**

Sometimes it’s best not to overdo the "DDD" when shaping the boundaries in your software architecture.

Using techniques like EventStorming you might achieve a clear conceptual model with well defined subdomains that domain experts agree with.

But it’s also important to analyse data flows: What information does a subdomain need from other subdomains to apply rules and make decisions?

Recently I hit this scenario...

1/2

**#ddDesign #ddd #swArch #eda**

Sometimes it’s best not to overdo the "DDD" when shaping the boundaries in your software architecture.

Using techniques like EventStorming you might achieve a clear conceptual model with well defined subdomains that domain experts agree with.

But it’s also important to analyse data flows: What information does a subdomain need from other subdomains to apply rules and make decisions?

Recently I hit this scenario...

1/2

**#ddDesign #ddd #swArch #eda**

Sometimes it’s best not to overdo the "DDD" when shaping the boundaries in your software architecture.

Using techniques like EventStorming you might achieve a clear conceptual model with well defined subdomains that domain experts agree with.

But it’s also important to analyse data flows: What information does a subdomain need from other subdomains to apply rules and make decisions?

Recently I hit this scenario...

1/2

**#ddDesign #ddd #swArch #eda**

Sometimes it’s best not to overdo the "DDD" when shaping the boundaries in your software architecture.

Using techniques like EventStorming you might achieve a clear conceptual model with well defined subdomains that domain experts agree with.

But it’s also important to analyse data flows: What information does a subdomain need from other subdomains to apply rules and make decisions?

Recently I hit this scenario...

1/2

**#ddDesign #ddd #swArch #eda**

Where should you put the anti-corruption/translation layer when migrating from a legacy system?

1. in the legacy
2. in new code
3. a dedicate translator service

A benefit of 1: fully encapsulate the legacy model and prevent it leaking

A benefit of 2: teams don't have to make PRs in multiple codebases for the same feature (when the ACL needs to change)

1/2

#architectureModernization #legacyMigration #softwareArchitecture #ddDesign #domainDrivenDesign

When modernizing your legacy systems, be careful not to automatically assume that the language your business and domain experts use is correct and should be reflected in your new architecture.

Their language might be influenced by your legacy systems and not an accurate reflection of the concepts in your domain.

Here is the kind of conversation I've had many times...

1/3

#ddDesign #domainDrivenDesign #softwareArchitecture #architectureModernization #archModernization

- are there any business rules or calculations that span all of this data?

- does all of this data need to always be consistent?

If you answer "no" to both, you should consider aggregating the data in the UI or a BFF.

But you may also need to do advanced searching across the combined data. This could push you towards a single subsystem although a separate search-oriented subsystem is a common option (especially as you need to search across more diverse data).

2/2

#ddd #ddDesign #swArch

- are there any business rules or calculations that span all of this data?

- does all of this data need to always be consistent?

If you answer "no" to both, you should consider aggregating the data in the UI or a BFF.

But you may also need to do advanced searching across the combined data. This could push you towards a single subsystem although a separate search-oriented subsystem is a common option (especially as you need to search across more diverse data).

2/2

#ddd #ddDesign #swArch

- are there any business rules or calculations that span all of this data?

- does all of this data need to always be consistent?

If you answer "no" to both, you should consider aggregating the data in the UI or a BFF.

But you may also need to do advanced searching across the combined data. This could push you towards a single subsystem although a separate search-oriented subsystem is a common option (especially as you need to search across more diverse data).

2/2

#ddd #ddDesign #swArch

- are there any business rules or calculations that span all of this data?

- does all of this data need to always be consistent?

If you answer "no" to both, you should consider aggregating the data in the UI or a BFF.

But you may also need to do advanced searching across the combined data. This could push you towards a single subsystem although a separate search-oriented subsystem is a common option (especially as you need to search across more diverse data).

2/2

#ddd #ddDesign #swArch

- are there any business rules or calculations that span all of this data?

- does all of this data need to always be consistent?

If you answer "no" to both, you should consider aggregating the data in the UI or a BFF.

But you may also need to do advanced searching across the combined data. This could push you towards a single subsystem although a separate search-oriented subsystem is a common option (especially as you need to search across more diverse data).

2/2

#ddd #ddDesign #swArch

📣New DDD Hamburg Meetup📣

I’m very happy that @bitboss will share his insights on Quality Storming on July 17. @wps will provide location and catering. RSVP here: https://www.meetup.com/de-DE/ddd-hh-domain-driven-design-hamburg/events/301976327/?slug=ddd-hh-domain-driven-design-hamburg&eventId=301976327

#dddhamburg #dddesign #collaborativemodeling #qualitystorming

📣New DDD Hamburg Meetup📣

I’m very happy that @bitboss will share his insights on Quality Storming on July 17. @wps will provide location and catering. RSVP here: https://www.meetup.com/de-DE/ddd-hh-domain-driven-design-hamburg/events/301976327/?slug=ddd-hh-domain-driven-design-hamburg&eventId=301976327

#dddhamburg #dddesign #collaborativemodeling #qualitystorming

📣New DDD Hamburg Meetup📣

I’m very happy that @bitboss will share his insights on Quality Storming on July 17. @wps will provide location and catering. RSVP here: https://www.meetup.com/de-DE/ddd-hh-domain-driven-design-hamburg/events/301976327/?slug=ddd-hh-domain-driven-design-hamburg&eventId=301976327

#dddhamburg #dddesign #collaborativemodeling #qualitystorming

📣New DDD Hamburg Meetup📣

I’m very happy that @bitboss will share his insights on Quality Storming on July 17. @wps will provide location and catering. RSVP here: https://www.meetup.com/de-DE/ddd-hh-domain-driven-design-hamburg/events/301976327/?slug=ddd-hh-domain-driven-design-hamburg&eventId=301976327

#dddhamburg #dddesign #collaborativemodeling #qualitystorming

📣New DDD Hamburg Meetup📣

I’m very happy that @bitboss will share his insights on Quality Storming on July 17. @wps will provide location and catering. RSVP here: https://www.meetup.com/de-DE/ddd-hh-domain-driven-design-hamburg/events/301976327/?slug=ddd-hh-domain-driven-design-hamburg&eventId=301976327

#dddhamburg #dddesign #collaborativemodeling #qualitystorming

It's not "overengineering" it's "modeling the solution".

#DDDesign #DomainModeling #FixPrimitiveObsession

Is my table really an address?

Or is this company starting to stretch their software to support use cases it wasn't originally designed for?

Is this a harmless hack or are they taking the current domain model in a bad direction?

The ravioli was good in any case.

#ddDesign #domainDrivenDesign #architectureModernization

1. which team has the best knowledge of this concept?

2. which team works on features most related to this?

3. which team's cognitive load will be impacted the most by this?

4. which team will be incentivized to build the best implementation?

5. which team works closest with the relevant domain experts?

This isn't the only important aspect, but it is an important one.

2/2

#socioTechnicalArchitecture #softwareArchitecture #ddd #domainDrivenDesign #eventDrivenArchitecture #ddDesign

1. which team has the best knowledge of this concept?

2. which team works on features most related to this?

3. which team's cognitive load will be impacted the most by this?

4. which team will be incentivized to build the best implementation?

5. which team works closest with the relevant domain experts?

This isn't the only important aspect, but it is an important one.

2/2

#socioTechnicalArchitecture #softwareArchitecture #ddd #domainDrivenDesign #eventDrivenArchitecture #ddDesign