Unveiling “Recommender Algorithms”: A Comprehensive Guide on Recommendation Systems | October 25 2025, 17:36

I finally released a book on #RecSys! It’s called Recommender Algorithms, where I’ve compiled over 50 recommendation algorithms with detailed mathematical derivations, thorough explanations, and code examples.

https://www.testmysearch.com/books/recommender-algorithms.html

It all started early this spring in Germany, when I attended an ACM conference and sketched out the first structure of the book while analyzing the talks from the RecSys track. And now, just six months later, it has come to life.

Why did I write it? Because neither online nor in print is there a single, accessible resource that deeply explores recommendation algorithms of various types and purposes. There are articles focused on small subsets, but collecting and systematizing approaches—from foundational methods to the very latest—seems to have never been done before. I don’t know if I succeeded, but I’d love to hear your feedback.

Please like & share!

P.S. Click at READ SAMPLE to see the first 40 pages. The table of contents is there as well.

https://www.testmysearch.com/books/recommender-algorithms.html

https://www.testmysearch.com/books/recommender-algorithms.html

AI Salesbots at Your Door: The Future of Autonomous Presentations | October 16 2025, 15:47

I’m telling the manager now, why do we need to present our AI solution, it’s AI, let it present itself. I imagine that in the near future, bots will be knocking on doors to sell themselves (and maybe not just themselves), while the door will have built-in bot protection.

Gold and Gadgets: Tracing Global Influence and Metal Monopolies | October 14 2025, 03:13

Rajesh Exports states on their website that they process 35% of the gold mined on the planet. Of course, they are exaggerating, but overall, India and Rajesh do shape the market. It turns out that 11% of all the gold on the planet is adorned on Indian women. Additionally, it was found that in 1947, 70% of all mined gold was in the USA. From 1934 to 1970, it was legally prohibited for private individuals to own gold in the USA. Approximately 22% of all the gold ever accounted for on the surface of the Earth has been mined from a plateau in South Africa called the Witwatersrand. And if you consider all the gold mined throughout history, it would amount to less than an Olympic swimming pool.

China buys up silver, with India not far behind. Interestingly, platinum is significantly used in the production of catalytic converters for vehicles – almost 40% of the global production goes there. China, of course, holds much of this production.

Practically every smartphone, tablet, or touchscreen monitor that we use is coated with a thin layer of indium tin oxide (ITO). This material has a unique combination of properties: it is almost completely transparent while also conducting electricity excellently. This allows the screen to register your touches.

Although lithium is now strongly associated with batteries, historically and still today, a significant portion of it is used in the production of glass and ceramics.

From Vision to Bookshelf: Launching “Recommender Algorithms” | October 13 2025, 11:54

Finally, I have released a book! It is called Recommender Algorithms — it contains more than 50 recommendation algorithms with mathematical explanations, detailed descriptions, and code examples.

It all started early in the spring in Germany, when I attended the ACM conference and made the first sketches of the book’s structure, analyzing reports on the RecSys stream. And now, six months later, the book has been published.

Why did it appear? Because there is no single, accessible source either online or in print where the recommendation algorithms of various types and purposes are thoroughly examined. There are articles focused on narrow aspects, but to collect and systematize the developments — from fundamental to the most recent — until now, it seems, no one has managed to do it for some reason. Maybe no one needed to. Suddenly, I found I needed to. I don’t know if I succeeded, but I am eager for your feedback.

Available on Amazon and Barnes and Noble. There is a Russian automatic translation (surprisingly, but very decent), but I do not know how to sell it yet.

https://www.testmysearch.com/books/recommender-algorithms.html?FB

(This is not my only book, but today — just about this one.)

Decoding Solr and Lucene: Engineering Insights and Algorithms | October 06 2025, 17:11

Preparing a book for publication on Solr&Lucene. What do you think about publishing such a translation on Amazon? 🙂

The book is about algorithms and under-the-hood engineering. I haven’t seen books from this angle yet, maybe someone will find it interesting.

When Pigs Outsmart Technology: The Failure of Precision Feeding in Large Farms | October 05 2025, 17:01

Today I learned how scientific achievements fly under a pig’s tail when faced with reality.

There’s this thing called precision feeding in pig farming. The gist is: a pig has an RFID chip attached to its tag (actually to its ear), and when it wants to eat, it sticks the tag into the feeder – and a special sensor reads its data and dispenses exactly as much feed from the machine as it should, also recording in a database how much and when it was given. If the pig sticks its tag in too early, the feed machine won’t dispense any. The idea is to reduce feed costs, improve growth and health of the animals, and lessen environmental pollution (less uneaten feed).

It seems like a great idea. However, such a system doesn’t work where there are large populations – it only works in specialized productions with few pigs, where almost all are known by name.

Why doesn’t it work on a large scale?

Because pigs are very cunning and quickly adapt. One pig inserts a tag, and then the one higher in the hierarchy chases it away and eats what isn’t meant for it.

Whole classes of oppressed arise, whose role is to insert the tag so that the authorities can gorge themselves. In the end, chaos ensues and no precision is achieved.

This is how pigs oppose technological progress.

The Surprising Origins of the Word “Tumbler” for Drinking Glasses | October 05 2025, 15:32

In our language, glasses are called tumblers. I decided to find out why, because a tumbler is essentially an acrobat.

There are two mutually exclusive theories. According to one, the original tumbler glasses had a rounded or slightly convex bottom, which allowed them to “rock” or “tumble” (to tumble), but not tip over completely. So, a tumbler in this sense is kind of like a “weeble.” According to the other, they were specifically made so they could not be put down on the table open, because, say on a ship, they could tip over and the valuable rum would spill out.

Exploring the Chaos Game: Creating Fractals From Randomness | October 04 2025, 15:32

I read something interesting today. About fractals. If you take any three points that form a triangle, and then a fourth point anywhere, and subsequently throw a dice, the faces of which are assigned to the first three points. Next, you move from the current point towards the point corresponding to the result on the dice and place a new point halfway; this becomes the new current point. After many iterations, the points start to form the Sierpinski triangle – the one shown in the attached picture. Intuitively, you would think the triangle should be fully filled because it involves random movements in three directions from a randomly chosen point, but no. Moreover, it works even if the starting point is inside the future empty triangle (yes, a few points will disrupt the picture, but that’s it). If you start our experiment with five or six points instead of three, different shapes will form – see the attached picture. This graphical method is called the Chaos Game.

By the way, it may seem obvious, but in case you wondered — all the presented figures have zero area.

If you take two triangles and with a probability p move towards random vertices of the first, and with (1-p) towards random vertices of the second, you end up forming a Barnsley fern (picture №2).

I love such things because they seem like magic at first glance 🙂

(It’s a kind of problem from the same class as the synchronization of metronomes)