Type annotations are what make statically typed object-oriented languages like Java run faster and safer. Without annotations, every variable would effectively collapse to Object, forcing runtime casts. The code would work, but slower and with more runtime errors. Some type annotations may be inferred instead of being explicitly specified by a programmer. Not all though. In Java, for example, a number of hard-to-resolve challenges prevent us from inferring types of all objects. This is not a fundamental limitation of OOP itself. It’s a result of design trade-offs in Java and similar languages. In a perfect object-oriented language, all variable types would be inferrable.

We have a list of books in the books object. How do we remove a single book from it, given that we know its ID? We can do books.removeById(42). Alternatively, we can find it with books.findById(42) and then call b.remove(). Which option should we prefer, and why? The second choice is the better one. Not only because it’s more object-oriented, but also due to several practical advantages.

Automated tests help us write code faster. Unit tests immediately tell us when we break something. Integration tests calm us down, reducing the fear of shipping a failure to a user. But who are “us”? Programmers. What about our employers? How do automated tests help them? Automated tests protect their investments.

A few weeks ago, @horw released a new GitHub plugin that fixes GitHub issue titles: issue-title-ai. Once an issue is created, the plugin asks ChatGPT—or DeepSeek, or Claude—to improve its title. We’ve already integrated the plugin into objectionary/eo and a few other repositories. Works like a charm. What’s wrong with the titles the way they are, you may ask? Why do we need to ask ChatGPT to make them “better”? Because we want every issue—either a bug report, a feature request, or a question—to be formulated as a complaint. It seems that very few of us can do it on the first try. The help of AI is appreciated.

Wikipedia says that Bug Driven Development (BDD) is an anti-pattern. Raja Shankar Kolluru perfectly explains why. However, Florian Rappl argues that it’s not. Ben Winding believes that it’s better than TDD. In simple words, BDD is kind of like trying to build a plane while it’s flying, based on passenger complaints. Nobody builds planes like that (well, maybe Boeing and Airbus). However, a software team that practices BDD might demonstrate higher productivity.

Every ticket—a bug report or a feature request—is a short-term contract. You, the reporter, hire them to make a fix or implement a feature. They, the team of developers, do it for you—provided you pay, or their motivation is intrinsic—for example, in open source. The discussion that happens along the way may help clarify the requirements of the contract. It may also help the team convince you that the bug doesn’t deserve a fix. Also, it may help them deliver the fix to you and convince you to close the ticket. However, the discussion may also distract both parties if it loses focus.

Someone has submitted a bug report to your repository. You fix the bug. You close the bug report. Stop. This is wrong. You shouldn’t close it. Instead, you should ask the reporter to review your fix. Then, maybe, they will close the ticket. If they don’t, you make another fix, until they do.

What do you think is the most typical reason for delays in pull request reviews? A study at Google confirms that it’s the size—the more changes, the slower the review. Another study shows that it’s the emotional tone—anger and dominance expressed in comments are linked to a lower likelihood of a pull request being merged. A more recent study finds that it’s the author’s reputation: we merge PRs faster if we know the author. All of the above is true. In our projects, though, what often slows down PR reviews is the message: “CI failures are not related to my changes!”

How long should it take to know if your code is safe? Martin Fowler once said: 10 minutes. Ten years later, five hundred developers agreed. I disagree—with all of them. First, ten minutes is not enough for a proper build, even for a small software system. Second, ten minutes is too much for a build that we run from the IDE after every one-line edit. We need a finer-grained classification of builds: from bullet-fast to thorough and dead slow.

My first attempt to contribute to an open source repository was a miserable failure. I picked a Java repository I was already using (Glassfish Jersey), created a unit test for an existing class, submitted a patch (there were no pull requests at that time), and… it was merged. I got excited and submitted another unit test in a new patch. No surprise, the repository owners asked me to stop fooling around: apparently, they didn’t need unit tests just for the sake of it. I quickly lost interest in making changes to anyone else’s code bases and started working on my own stuff instead. Don’t repeat my mistake! Becoming a contributor to an existing code base is a much faster path into the open source world and is far more rewarding. Here are some things to keep in mind to make your journey to success even faster—especially if you are just a beginner making your first pull requests.

Можно бесконечно смотреть на три вещи: как горит огонь, как течёт вода и как политические новости сменяют друг друга в любимых Telegram-каналах. Последнее увлекает особенно сильно. Потому что, в отличие от божественной непостижимости узоров пламени, в информационном хаосе разобраться, конечно же, можно. Я, например, регулярно получаю анонимные письма от самых активных из тех, у кого это прекрасно получается. В своих письмах они подробно и убедительно анализируют геополитическую повестку, находят виноватых (обычно это евреи) и, в целях безопасности, требуют уничтожить письмо сразу после прочтения. Менее буйные писем не пишут, но, если их спросить, без тени сомнения расскажут, что происходит и кто виноват.

How would you design a class that abstracts, say, a file on a disk with certain properties? Let’s say you need to be able to check whether the file exists on the disk or has already been deleted. Would you create an object first and then call the exists() method on it, or would you call Disk.fileExists() first and only then, if TRUE is returned, make an instance of the File class and continue working with it? This may sound like a matter of taste, but it’s not that simple.

One of the most frequently asked questions I hear from junior programmers (no matter their age) is: What should I focus on now to build the best career I can? There are multiple options, including creating a startup, getting a PhD, contributing to open source, working for Google, and many others. In my opinion, the most common mistake is trying to get rich fast. Obviously, money matters and is the ultimate metric of career success, but trying to get it too early is nothing more than gambling with your life at stake. Instead, I suggest focusing on winning some “medals,” which can later be converted to cash, not the other way around.

If you, like me, are not a patent attorney and don’t understand patent law, but your boss asks you to turn your recently written piece of code into a patent, read on. The boss most probably won’t ask you to write the entire patent. Instead, he will ask you to prepare a quick summary of the invention (usually, a few slides) and then a hired lawyer will turn it into a full-scale patent application. If you understand the purpose of patents, the mechanics of patent offices, and the format of a patent claim, you will do just fine.

А знаете, какое самое популярное по числу просмотров видео на YouTube? Вот это. 14 миллиардов просмотров за менее чем семь лет. И таких видео много. Задаюсь вопросом, о чем эта песня? Чему она учит? Какой вообще в ней смысл? С моей точки зрения, сформированной когда-то давно сказками Сергея Михалкова, Самуила Маршака и Агнии Барто, в этой песне смысла нет. Но ведь он должен быть, раз её посмотрели и оценили по достоинству сотни миллионов родителей и детей! Нет, не должен. Всё просто: что сейчас нравится миллионам, то и является эталоном качества. Но ведь так было не всегда.

Я не историк и даже в школе историю не любил. Не любил, но верил, что так все и было: и Французская революция, и восстание Спартака, и война Аттилы с Римом, и охоты на мамонтов с последующими иллюстрациями на стенах древних пещер. Все это было именно так, как рассказывали нам учителя истории (они в моем детстве почему-то часто менялись). Позже, когда появился Internet, я узнал о Новой Хронологии и стал скептиком — перестал верить на слово тому, что говорят историки. Стал в любом описании событий прошлого искать альтернативные версии. Еще позже я узнал, что это называется конспирологией и в порядочном обществе осуждается, Пелевин не даст соврать.