[HN Gopher] UML diagram for the DDD example in Evans' book
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       UML diagram for the DDD example in Evans' book
        
       This project uses UML diagrams to illustrate the structure and
       behavior of the DDD example--a cargo shipping system--from Eric
       Evans' book (Domain-Driven Design: Tackling Complexity in the Heart
       of Software).
        
       Author : takaakit
       Score  : 43 points
       Date   : 2025-04-18 19:40 UTC (3 hours ago)
        
 (HTM) web link (github.com)
 (TXT) w3m dump (github.com)
        
       | ak_111 wrote:
       | What happened to UML? I remember it was everywhere in enterprise
       | computing 20 years ago but seems to have disappeared now.
       | 
       | Is it still around or did it go the way of SOAP, Java Applets? If
       | not, what has replaced it?
        
         | zabzonk wrote:
         | Just my opinion, but I think that folks realised it was not
         | much use for initial design, but could work reasonably well for
         | documentation of existing systems.
        
           | devenson wrote:
           | Documenting existing system dependencies using the product
           | which which I'm a founder:
           | 
           | https://schematix.com/video/depmap
           | 
           | Like UML deployment diagrams, but our models are interactive
           | and can be queried.
           | 
           | We also have a large customer doing DDD modeling and then
           | generating code directly from the models they build.
        
         | riffraff wrote:
         | UML as a methodology seems to have disappeared, but bits of it
         | (e.g. sequence diagrams) seem to have been absorbed by the
         | profession at large.
        
         | ramon156 wrote:
         | We still learned UML diagrams in school in 2019, though I have
         | to say I haven't used it anywhere in my job
        
           | neilv wrote:
           | In the case of UML, I think enterprise consulting and tool
           | sales might've already obscured much of the real value of
           | semiformal methods, before a CS curriculum could sour
           | students on it.
           | 
           | With ZIRP growth scheme startups hopefully over, and more of
           | us having to get jobs building systems that work reliably and
           | sustainably, we might gain a new appreciation for system
           | modeling.
        
         | dcminter wrote:
         | I'm kind of hazy about where the boundaries between bona fide
         | UML and PlantUML are, but PlantUML is in pretty common use in
         | my world - more for sequence diagrams and state diagrams than
         | class diagrams though. Of course PlantUML has competition from
         | things like Mermaid, but they're all much of a muchness.
         | 
         | My very non-scientific impression is that tools like Rational
         | were mostly used for drawing class diagrams and ... that just
         | turned out not to be that useful because the tooling didn't
         | exist to round-trip changes in the code back into the diagrams
         | meaning the diagrams lost parity with the code rather quickly.
         | It was sort of useful in the linear design/code/deliver world,
         | but we're a lot more iterative now.
        
           | nickthegreek wrote:
           | I just learned about UML earlier today when I wanted to bring
           | in a mermaid flowchart into lucidchart. If you bring in
           | mermaid using lucidchart, it makes it a raster image. But if
           | you use UML markup, you can ungroup it and modify. I couldn't
           | get a good way to convert from mermaid to UML markup that
           | lucidchart could handle. Ended up a dead end for me.
        
             | dcminter wrote:
             | On a similar note I've had various annoyances with wanting
             | to round trip diagrams from Mermaid or PlantUML into Miro
             | and vice versa. There doesn't seem to be much out there to
             | facilitate this, which is strange, because it feels like a
             | very enterprisey thing to want to do.
             | 
             | There's probably a SaaS product in it for someone
             | sufficiently interested in the topic... probably not at
             | unicorn scale, but enough for a side income perhaps?
        
         | NBJack wrote:
         | Just another data point that the "low code/no code" revolution
         | sputtered out over a decade ago.
         | 
         | I still see and use a small subset of UML for more complex
         | architecture discussions, but that's about it (i.e. service
         | nesting, message passing, etc.).
        
         | whartung wrote:
         | I think folks upgraded to GML [0]
         | 
         | [0] https://wiki.c2.com/?GalacticModelingLanguage
        
           | oleggromov wrote:
           | This is wonderful. Thank you.
        
           | icedchai wrote:
           | I love it. Even with GML, you run into problems. Diagramming
           | is an art more than a science. You have to know your audience
           | (technical people, marketing types, investors, customers...)
           | 
           | Leaving stuff out is also important. (Example: Unless you're
           | building a DNS related product, don't bother to include "DNS"
           | in your diagrams. Your use of it is assumed.)
        
         | titaphraz wrote:
         | UML was a scam really. They took a lot of very useful diagrams
         | and created a absolute behemoth of unproven system to develop
         | software and sold it.
         | 
         | The diagrams are very nice and useful. But the UML as a
         | process, if taken literally, it a total disaster.
        
           | hmartin wrote:
           | > UML was a scam really.
           | 
           | Objectively and utterly wrong.
        
       | neilv wrote:
       | I used to work heavily in this kind of system modeling
       | (developing tools for it, and dogfooding), and still use it when
       | high-value for figuring out or communicating an aspect of a
       | system.
       | 
       | Here's a challenge, to help appreciate the nature of these: try
       | to find an error in the diagrams.
       | 
       | It's usually harder than you might think, since, even when you
       | know the notation and metamodel semantics, it's information-dense
       | talking about a domain.
       | 
       | You usually have to know or learn a lot about the domain, and/or
       | have an domain expert you can walk through it exhaustively,
       | before you can find errors.
       | 
       | And an error can be whopper: a single graph edge missing, or
       | between the wrong vertices, or with the wrong adornments can have
       | huge implications.
       | 
       | For example, large amounts of work that have to be redone, or a
       | project abandoned, or a mess that takes 10x longer than it should
       | to write, and 10x the tech debt going forward with a bad
       | architecture, or a fundamental security flaw.
       | 
       | One of the mistakes many people make is treating formalized
       | diagrams as "marketecture" visuals, like they only need for
       | handwaving sales presentation slides, where there's some kind of
       | visual for every concept they want to be able to literally point
       | to.
       | 
       | Nope, if you have software engineers and domain experts
       | communicating and reasoning about your system in only the fuzzy
       | terms of sales/exec presentations, you're really stabbing
       | yourself in the face.
        
       | karlgkk wrote:
       | Apropos of nothing, all of the major ai models have gotten really
       | good at turning a pdf or document into uml
       | 
       | Not great, mind you. 80% of the way there still saves an hour of
       | your time tho
        
         | fuzzer371 wrote:
         | How about we ditch the AI slop
        
       | throw_m239339 wrote:
       | It's useful to convey architectures. The problem is that UML has
       | been abused by some vendors that implemented bad software based
       | on "Rapid UML Development" and it soured a lot of developers.
       | Also it is very old java OO oriented. But Sequence diagrams are
       | still in use.
        
         | dcminter wrote:
         | OO yes, but not Java particularly. I was using Rational tools
         | with C++ projects well before Java was getting any visibility.
        
       | firesteelrain wrote:
       | These diagrams make a lot of sense if you understand the symbols
       | and the relationships plus aggregations. You can easily talk to
       | them. I use these diagrams with non technical people all the time
        
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       (page generated 2025-04-18 23:00 UTC)