yeah, I remember not understanding domain driven design
I started working as a professional programmer in the mid-90s when three-tiered design was all the rage: a data access layer, a business logic layer, and a presentation layer. It seems that nobody actually knew what “business logic” was even supposed to be, because I kept inheriting projects where all the middle tier did was hand data objects from the data layer to the UI. In theory this prevented the UI from being fundamentally bound to the data access, but all three layers were always written in Visual Basic which got kicked to the curb in a few years anyway.
My first tech job was writing test harnesses for DCOMs. Your post was a weird trip down memory lane.
Business logic would be transformations to the data. Like for a spreadsheet, the data layer would handle the reading/writing of files as well as the storage of each cell’s content. The business logic layer would handle evaluating each of the formulas in the cells, and the presentation layer draws it on the screen.
I think the part where it gets confusing is that each of these layers are pretty tightly coupled. The end destination of the presentation layer might change, one might show it on a GUI, another might print it, and another might convert it to pdf or html, but each of those presentation layers needs to understand the data that it is presenting, so it’s tightly coupled to the data layer. Same with the businesses logic layer, though it’s tightly coupled on both the input and output sides. The design of the data layer constrains the possibilities of the other two, so it’s hard to draw a clear boundary between the layers because they all need to know how to walk the same data.
My mental flow chart for this is more of a data layer in the middle instead of business logic, where business logic is to the side with arrows going both ways between it and data layer, then the presentation layer also accessing the data layer directly, which I suppose is a different permutation of what you described.
Though another way to look at it does make sense. For a website, think of the database as the data layer, the server scripts as the business logic layer, and the client side scripts/html/css as the presentation layer. That one also follows the layered approach where the presentation layer is talking with the business logic layer.
Abstraction is not very compatible with concurrency, so as well as your your beautiful abstract API, you also need some ‘cut through the layers’ functions to return the underlying classes you need to synchronise on. Now you have a right mess that’s incredibly hard to understand, infuriating to debug, and impossible to refactor. Best you can do is put another layer of abstraction on top. Repeat every six months.
That’s just bad interface… When you design an API as if operations were independent, but they aren’t, you run into these issues.
Don’t add “cut through the lawyers” functions, fix your interface.
Yeah, well-designed abstraction can help enable more concurrency. That said, concurrency isn’t easy at any point once there’s shared data that needs to be written to during the process. Maybe it’s not so bad if your language has good concurrency support (like monitor classes and such that handle most of the locking behind the scenes), but even then, there’s subtle pitfalls that can add rare bugs or crashes to your program.
Pack it to lambda and name it microservice.
They look so painfully awkward, like a parent should be telling them to knock it off or something.
If you haven’t seen the vid it’s 500 levels of awkward cringe that’s hard to watch. Had to do with one of the MS version releases. They’re acting so awkward you can’t tell if they’re yakked out in coke or just that socially awkward. Full disclosure I’d be worse than them in that situation, just calling it like it is.
Sometimes tech presentations make me feel really bad for the person giving it. They are up there trying their best but clearly don’t have the skills to do more than just communicate information but still try to make their presentation cool and fun and it just falls flat.
Anyone can be cool, but not everyone can be cool on demand or on stage.
Though on the other hand, just because a presenter can pull off the cool factor, it doesn’t mean what they are presenting is actually cool. The coolness of a presentation has no correlation with the coolness of what is being presented, unless that coolness is just information about the product (though even then, they are probably skipping over the flaws and enshitification).
100% Ballmer is yakked out on coke.
At least one of them is a pedophile, so you’re probably not wrong
I recently started a new job. We use Java. There’s a class that does a few things based on explicit arguments only to decide whether to use an FTP or file output, and you supply all parameters yourself. A whole ass Rube Goldberg machine that could be replaced by a single line of Files.writeString.
Also, there’s a great video on YT “Stop writing classes” that is incredibly relevant.
Yeah, Java’s enforcement of everything must be a class put me off of the language right from the start. I was already used to C++ at that point and hated that I couldn’t just write a quick little test function to check something, it needed a bunch of boilerplate to even get started.
I still think C++ has a great balance between object oriented and sequential programming. Not sure if it’s the best, but I can’t think of ways to improve on it, other than built in concurrency object stuff (like monitor classes that have built in locks that prevent more than one thread from accessing any of its functions at the same time, basically guaranteeing any code in it has mutual exclusion).
This hits.
I stepped into a similar implementation. Took like 6 months and 10 people to support…
… changing the URL of the sftp server we connected to.
Junior devs not abstracting anything and now the app is unmaintainable
Exactly, have fun trying to get test coverage without dependency injection
with patch("some_file.requests.get", side_effect=SomeException("oh no")): result = func_using_requests()Though not every language makes mocking as easy, and multiple responsibilities in a single function can quickly get messy.
Oh I’m fully aware that python lets you cheat dependency injection with patch, its one of the many things python teaches developers to do wrong, which leads them to be unable to use any other language.
Is it any more maintainable with four levels of abstraction?
There’s a middle ground
2 layers of abstraction is the gold standard
Depends on the abstractions
Just got out of a discussion with a supplier. We can do what we needed by connecting to the database. Instead we have to go through four layers of different tech to arrive at the same point in the database otherwise it’s not compliant. That the supplier needs to sell a license for those layers is purely coincidental.
Obviously don’t have the full context, but rarely is it ever advisable to give third parties direct access to a database. There are many reasons for this, like, for example, the fact that doing so makes schema migrations practically impossible.
Always favor composition over inheritance if you can.
All absolute statements are false.
all of them?
Seems perfectly cromulent to me!
Yes. They just introduced a paradox to our logic, therefore everything is true.
But also no, because that contradiction also implies everything is false.
Hell yeah, peertube has the video: https://peerate.fr/w/2ktPxQgBvDHdHWzogVTRvH
they really made their domain pee rate dot france huh
Lol that’s a nice catch
Edit: maybe “peer at eFrance” or something that makes more sense in french.
I don’t get it.
Does it have something to do with a certain place in France smelling of piss?
It’s… glorious.
DEVELOPERS, DEVELOPERS, DEVELOPERS, DEVELOPERS!!!
COPILOTS, COPILOTS, COPILOTS, COPILOTS!!!
There, I updated it for you and I hate it.
you missed the best part
AAAAHHHHRRRRGGGHHHHHHHAAAAAAAA! sweat pouring off balmer as his body goes into shock from the pain
His mutant power is absorbing all of the cocaine in a 20 mi radius.
https://www.youtube.com/watch?v=KMU0tzLwhbe
this little gem turned 20 years old on Jan 24 this year.
Can confirm.
Why should I want simplicity? I want to make unnecessarily complex programs to gatekeep those pesky junior programmers.
That’s how you get that job security…
That’sthejoke.jpg
I think what they meant is that making it complex gets you job security
Abstraction layers is simplicity given a complex enough bottom.
I’ve been around long enough to question this kind of advice. It depends, in so many ways, on the goals, strategies, and platforms.
A complex bottom may have difficulty mating with a simple top
UwU
Me making my devs create a base exception for handling all exceptions that contain messages for display in the UI. Which has a parent base exception we use for all our exceptions which of course has Exception for it’s parent.
I hate our codebase but I’m so close to killing off 15 year old vb.net code. If the left me alone and I had the time I spent in meetings or 20 mins between meetings everything on our roadmap for the next year would have been done 2 years ago.
that image is from the whitest gif of all time
Americans love to make everything about skin color…
We tried to get a black dev onboard, but she refused adding 4 layers of abstraction.
Where did the gif come from
Microsoft conference back in (from memory) nineties with Steve Ballmer (sp?) dancing around stage screaming developers! Developers! Developers! since that’s what market domination is all a outif your are making an operating system.
