The word “deadline” probably originated from the 19th century and described a line drawn around a prison or a camp of prisoners. A prisoner that crossed that line was shot. Think about this definition the next time someone “draws a deadline” around you; it will undoubtedly open up new perspectives.


A quick online search has revealed that a company called PayPal has stolen my idea and even copied part of the name. Shame on them! Joking aside, try to find a name similar to “Paypal” that is not the name of an existing company. It’s hilarious!

Any dependency

We can only invert dependencies when we have control over the code on both sides of the dependency. If we have a dependency to a third-party library, we cannot invert it since we don’t control the code of that library.

Hexagonal source

The primary source for the term “Hexagonal Architecture” seems to be an article on Alistair Cockburn’s website.


The use case would also have to make sure that no other money transfer to and from the source and target account is happening at the same time to avoid overdrawing an account.

30000 lines

It was actually a conscious architecture decision (by our predecessors, mind you) that led to those 30000 lines being in a single class. To change the system at runtime without redeployment, it allowed to upload compiled Java bytecode in a .class file, and it only allowed upload of a single file, so this file had to contain all the code.


Does that sound familiar to you? You choose JPAJava Persistence API as an OR mapper because it’s the thing people use for this problem. A couple months into development you curse eager and lazy loading and the caching features and wish for something simpler. JPAJava Persistence API is a great tool, but for many problems, simpler solutions may be, well, simpler.


This method is just a placeholder for any bootstrapping logic that is necessary to expose our web adapters via HTTPHypertext Transfer Protocol. We don’t really want to implement this ourselves.


Imagine this sentence in a book about construction engineering or, even scarier, in a book about avionics! Most of us, however, are not building the software equivalent of a skyscraper or an airplane. And software is soft and can be changed more easily than hardware, so sometimes it’s actually more economic to (consciously!) take a shortcut first and fix it later (or never).


I’m the “Defender” personality type, and if I were a dog, I would apparently be a Pit Bull.

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