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Asbjørn Ulsberg<a href="https://sfba.social/@williampietri" class="u-url mention" rel="nofollow noopener" target="_blank">@williampietri</a> You are quite correct, and this is why the idea of software development being a “sociotechnical” practice is gaining traction. <a href="https://hachyderm.io/@trondhjort" class="u-url mention" rel="nofollow noopener" target="_blank">@trondhjort</a>, @nick_tune, and others in the <a href="https://icosahedron.website/tags/DDDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#DDDesign</a> community writes and talks a about this in length. It’s a tough nut to crack, though. Software development is still being seen and marketed as a masculine, technical skill that can (even must) be done successfully in isolation from the people the software is being built to serve. This view alienates the very people our field of work need more of to prosper, and locks us into a dark spiral of negative reinforcing toxic masculinity of what I like to call “technical masturbation”.An important realization of being a software developer is to acknowledge that since software development is a very young and social science, we understand perhaps even less of what we do than economists do of economics. We are mere alchemists throwing ingredients into a cauldron hoping it will turn into gold.

Nick TuneThere's quite a few DDD people on Bluesky so I created a list: <a href="https://bsky.app/profile/did:plc:rckvbasit6ovva2bg7dvafdp/lists/3l7y76qe5vz2u" rel="nofollow noopener" translate="no" target="_blank">https://bsky.app/profile/did:plc:rckvbasit6ovva2bg7dvafdp/lists/3l7y76qe5vz2u</a>If you know anyone who should be on the list, let me know.<a href="https://hachyderm.io/tags/ddd" class="mention hashtag" rel="nofollow noopener" target="_blank">#ddd</a> <a href="https://hachyderm.io/tags/domainDrivenDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#domainDrivenDesign</a> <a href="https://hachyderm.io/tags/ddDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#ddDesign</a>

Nick TuneOur next DDD London meetup has been scheduled.On Tuesday 19th November, Tim Mortimer will be talking about Executable Specifications.See you there.<a href="https://hachyderm.io/tags/dddLondon" class="mention hashtag" rel="nofollow noopener" target="_blank">#dddLondon</a> <a href="https://hachyderm.io/tags/ddDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#ddDesign</a> <a href="https://hachyderm.io/tags/domainDrivenDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#domainDrivenDesign</a> <a href="https://hachyderm.io/tags/bdd" class="mention hashtag" rel="nofollow noopener" target="_blank">#bdd</a><a href="https://www.meetup.com/dddlondon/events/303976744/" rel="nofollow noopener" translate="no" target="_blank">https://www.meetup.com/dddlondon/events/303976744/</a>

Nick TuneArchitecture 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 data1/3<a href="https://hachyderm.io/tags/architectureModernization" class="mention hashtag" rel="nofollow noopener" target="_blank">#architectureModernization</a> <a href="https://hachyderm.io/tags/ddDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#ddDesign</a>

Nick TuneOur conceptual understanding of a business domain plays a fundamental role in how we architect our software systems.For example, when we have specialised versions of a general concept - do we treat the variability as an attribute or specialized entities?See the attached image: if we consider a dealership to be one single entity with different shapes of profile, we might lean more towards a profiles subdomain.1/2<a href="https://hachyderm.io/tags/softwareArchitecutre" class="mention hashtag" rel="nofollow noopener" target="_blank">#softwareArchitecutre</a> <a href="https://hachyderm.io/tags/ddDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#ddDesign</a> <a href="https://hachyderm.io/tags/domainDrivenDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#domainDrivenDesign</a>

Nick TuneWith finest-grained events you would have around 100 event types, whereas only 8 with coarsest-grained events (and there are many variations in-between).Your choice could have a massive impact on the complexity and evolvability of your architecture, both for you and the consumers of your events.I judge every event on a case-by-case basis, but here are some things I look out for:- do consumers have to consume a high volume of events they are not interested in?2/3<a href="https://hachyderm.io/tags/ddDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#ddDesign</a> <a href="https://hachyderm.io/tags/eda" class="mention hashtag" rel="nofollow noopener" target="_blank">#eda</a>

Nick TuneEvent granularity is often a very tricky aspect of event-driven architecture. It usually requires a very deep understanding of your business domain and product strategy.Imagine a company with a product that:- has 8 lifecycles steps (e.g. started, cancelled, closed) - has 3 variations - is sold in 4 countries (customised to each)1/3**<a href="https://hachyderm.io/tags/eventDrivenArchitecture" class="mention hashtag" rel="nofollow noopener" target="_blank">#eventDrivenArchitecture</a>** **<a href="https://hachyderm.io/tags/softwareArchitecture" class="mention hashtag" rel="nofollow noopener" target="_blank">#softwareArchitecture</a>** **<a href="https://hachyderm.io/tags/ddDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#ddDesign</a>** **<a href="https://hachyderm.io/tags/domainDrivenDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#domainDrivenDesign</a>**

Nick TuneSometimes 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 **<a href="https://hachyderm.io/tags/ddDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#ddDesign</a> <a href="https://hachyderm.io/tags/ddd" class="mention hashtag" rel="nofollow noopener" target="_blank">#ddd</a> <a href="https://hachyderm.io/tags/swArch" class="mention hashtag" rel="nofollow noopener" target="_blank">#swArch</a> <a href="https://hachyderm.io/tags/eda" class="mention hashtag" rel="nofollow noopener" target="_blank">#eda</a>**

Nick TuneWhere 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 serviceA benefit of 1: fully encapsulate the legacy model and prevent it leakingA 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<a href="https://hachyderm.io/tags/architectureModernization" class="mention hashtag" rel="nofollow noopener" target="_blank">#architectureModernization</a> <a href="https://hachyderm.io/tags/legacyMigration" class="mention hashtag" rel="nofollow noopener" target="_blank">#legacyMigration</a> <a href="https://hachyderm.io/tags/softwareArchitecture" class="mention hashtag" rel="nofollow noopener" target="_blank">#softwareArchitecture</a> <a href="https://hachyderm.io/tags/ddDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#ddDesign</a> <a href="https://hachyderm.io/tags/domainDrivenDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#domainDrivenDesign</a>

Nick TuneIf you are looking for top-notch conferences to speak at then check-out Explore DDD which is held in Denver in April.The CFP is open until the end of this month.I've been to the conference numerous times and I'm always very happy to fully endorse Paul Rayner and his team for putting on a great event and treating speakers outstandingly well.It's a community of enthusiastic learners and nice people.<a href="https://exploreddd.com/cfp/" rel="nofollow noopener" translate="no" target="_blank">https://exploreddd.com/cfp/</a><a href="https://hachyderm.io/tags/ddd" class="mention hashtag" rel="nofollow noopener" target="_blank">#ddd</a> <a href="https://hachyderm.io/tags/ddDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#ddDesign</a> <a href="https://hachyderm.io/tags/domainDrivenDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#domainDrivenDesign</a> <a href="https://hachyderm.io/tags/softwareArchitecture" class="mention hashtag" rel="nofollow noopener" target="_blank">#softwareArchitecture</a>

Nick TuneWhen 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<a href="https://hachyderm.io/tags/ddDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#ddDesign</a> <a href="https://hachyderm.io/tags/domainDrivenDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#domainDrivenDesign</a> <a href="https://hachyderm.io/tags/softwareArchitecture" class="mention hashtag" rel="nofollow noopener" target="_blank">#softwareArchitecture</a> <a href="https://hachyderm.io/tags/architectureModernization" class="mention hashtag" rel="nofollow noopener" target="_blank">#architectureModernization</a> <a href="https://hachyderm.io/tags/archModernization" class="mention hashtag" rel="nofollow noopener" target="_blank">#archModernization</a>

Nick Tune- 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<a href="https://hachyderm.io/tags/ddd" class="mention hashtag" rel="nofollow noopener" target="_blank">#ddd</a> <a href="https://hachyderm.io/tags/ddDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#ddDesign</a> <a href="https://hachyderm.io/tags/swArch" class="mention hashtag" rel="nofollow noopener" target="_blank">#swArch</a>

Nick Tune...to group these in an email validation component because they are both rules about email. But they are not the same type of rule and serve different purposes. Rules that don't depend on state are often good candidates for value objects<a href="https://hachyderm.io/tags/ddDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#ddDesign</a>

Nick TuneIs 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.<a href="https://hachyderm.io/tags/ddDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#ddDesign</a> <a href="https://hachyderm.io/tags/domainDrivenDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#domainDrivenDesign</a> <a href="https://hachyderm.io/tags/architectureModernization" class="mention hashtag" rel="nofollow noopener" target="_blank">#architectureModernization</a>

Nick Tune1. 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<a href="https://hachyderm.io/tags/socioTechnicalArchitecture" class="mention hashtag" rel="nofollow noopener" target="_blank">#socioTechnicalArchitecture</a> <a href="https://hachyderm.io/tags/softwareArchitecture" class="mention hashtag" rel="nofollow noopener" target="_blank">#softwareArchitecture</a> <a href="https://hachyderm.io/tags/ddd" class="mention hashtag" rel="nofollow noopener" target="_blank">#ddd</a> <a href="https://hachyderm.io/tags/domainDrivenDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#domainDrivenDesign</a> <a href="https://hachyderm.io/tags/eventDrivenArchitecture" class="mention hashtag" rel="nofollow noopener" target="_blank">#eventDrivenArchitecture</a> <a href="https://hachyderm.io/tags/ddDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#ddDesign</a>

Nick Tune....and they are expensive to undo later, so you continue layering on new features exacerbating the problem. To be honest, it's inevitable. We can't predict the future. But that doesn't mean just YOLO everything.We can try to better understand where the business is heading, and we can speak up when it's time to stop adding more layers and fix the foundations.2/2<a href="https://hachyderm.io/tags/ddDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#ddDesign</a> <a href="https://hachyderm.io/tags/softwareArchitecture" class="mention hashtag" rel="nofollow noopener" target="_blank">#softwareArchitecture</a>

Nick TuneOne of the most fascinating things about software architecture is how choices in the past can have such a strong influence on the system for years to come. You might make a decision that seems trivial at the time, but new features get layered on top of your design's assumptions.These bakediin constraints limit how you can evolve the system,...1/2 <a href="https://hachyderm.io/tags/softwareArchitecture" class="mention hashtag" rel="nofollow noopener" target="_blank">#softwareArchitecture</a> <a href="https://hachyderm.io/tags/architectureModernization" class="mention hashtag" rel="nofollow noopener" target="_blank">#architectureModernization</a> <a href="https://hachyderm.io/tags/ddd" class="mention hashtag" rel="nofollow noopener" target="_blank">#ddd</a> <a href="https://hachyderm.io/tags/domainDrivenDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#domainDrivenDesign</a> <a href="https://hachyderm.io/tags/ddDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#ddDesign</a>

Nick TuneWhen beginning to modernize, should you start by designing the future state or spend some time exploring the current state?Sometimes people say "What's the point looking at the past? Let's go straight to the future state!"However, your existing systems and processes contain a lot of knowledge. Naively jumping to the future state without understanding the workings and constraints…1/2<a href="https://hachyderm.io/tags/architectureModernization" class="mention hashtag" rel="nofollow noopener" target="_blank">#architectureModernization</a> <a href="https://hachyderm.io/tags/legacyMigration" class="mention hashtag" rel="nofollow noopener" target="_blank">#legacyMigration</a> <a href="https://hachyderm.io/tags/ddd" class="mention hashtag" rel="nofollow noopener" target="_blank">#ddd</a> <a href="https://hachyderm.io/tags/domainDrivenDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#domainDrivenDesign</a> <a href="https://hachyderm.io/tags/ddDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#ddDesign</a> <a href="https://hachyderm.io/tags/eventStorming" class="mention hashtag" rel="nofollow noopener" target="_blank">#eventStorming</a>

Nick Tune.....helping business and technology people map out specific scenarios.This technique also forms a key part of Eric Evans Model Exploration Whirlpool which is also highly recommended.<a href="https://www.domainlanguage.com/ddd/whirlpool/" rel="nofollow noopener" translate="no" target="_blank">https://www.domainlanguage.com/ddd/whirlpool/</a>2/2<a href="https://hachyderm.io/tags/ddd" class="mention hashtag" rel="nofollow noopener" target="_blank">#ddd</a> <a href="https://hachyderm.io/tags/ddDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#ddDesign</a> <a href="https://hachyderm.io/tags/domainDrivenDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#domainDrivenDesign</a> <a href="https://hachyderm.io/tags/softwareArchitecture" class="mention hashtag" rel="nofollow noopener" target="_blank">#softwareArchitecture</a>

Nick TuneIt was wonderful watching <a href="https://mastodon.social/@yellowbrickc" class="u-url mention" rel="nofollow noopener" target="_blank">@yellowbrickc</a> facilitate a DDD/architecture workshop yesterday at PayFit France.She demonstrated one of the most effective, and simplest, techniques to perfection "Talk me through a concrete use case".She quickly helped a group map out the details and then make a decision about their architecture. It was really impressive.If you want to become a good facilitator then I recommend getting good at this skill.1/2<a href="https://hachyderm.io/tags/ddd" class="mention hashtag" rel="nofollow noopener" target="_blank">#ddd</a> <a href="https://hachyderm.io/tags/ddDesign" class="mention hashtag" rel="nofollow noopener" target="_blank">#ddDesign</a> <a href="https://hachyderm.io/tags/softwareArchitecture" class="mention hashtag" rel="nofollow noopener" target="_blank">#softwareArchitecture</a>

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