Nowadays, there are few people who choose books on the advice of their acquaintances. Most people use recommendation systems on specialized sites and, of course, read reviews. Book recommendation systems have revolutionized the way we consume literature. These systems help readers find books that match their interests and preferences, providing endless possibilities to expand one’s literary horizons. The primary advantage of book recommendation systems is personalization. They offer tailored recommendations based on individual reading habits, genres, authors, and other factors such as past ratings or reviews. This feature saves time and effort in searching for books manually while enhancing the overall reading experience. Additionally, it helps publishers and authors reach out to targeted audiences by promoting their new releases or lesser-known titles to interested readers. Each recommendation system is a unique algorithm. However, they also have a lot in common. For example, almost all systems evaluate the similarity of book

Cookie Cats is an extremely popular mobile puzzle game developed by Tactile Entertainment. It is a classic puzzle game in which the player must connect tiles of the same color to clear the field and win the level. There are also singing cats. As players progress through the game’s levels, they occasionally encounter gates that make them wait a certain amount of time or make in-app purchases to continue playing. In addition to encouraging in-app purchases, these gates serve the important purpose of giving players a forced break from the game, which will hopefully lead to increased and prolonged enjoyment of the game. Obviously, gates are profitable for the developers of the game. However, where is the best place to put the gate? Originally, the first gates were placed at level 30. This project asks you to analyze an AB test in which the creators moved the first gate in

There is no perfect website design. Even if it is honed many times, there will always be something that can be improved. As a rule, the quality of website design is evaluated not only in terms of visual beauty and usability, but also in terms of conversions, which it brings. These can be purchases of goods, applications with customer emails and phone numbers, clicks on certain buttons. All of this is measured and defined as conversion. The calculations of conversions themselves can be made in different ways: with Excel, internal CRM systems, as well as with programming languages and special mathematical libraries. Python is the go-to programming language for conducting A/B testing of different website design versions. A/B testing in Python can help to boost website conversion rates by experimenting with various designs and user experiences. With Python, web developers can easily monitor and analyze customers’ behavior on their websites,

Today, more than 3 years have passed since the COVID-19 pandemic began. During this time, dozens of high-quality tests have been developed. However, none of them is even 99% accurate. Can tests be wrong? Of course they can. What is the probability that a person really has COVID if the best test result is positive? To answer these questions, I downloaded data on the best coronavirus test in Russia so far, as well as data on the number of people infected and simulate 1 million tests in Python. Links Python code in Google Colab

Have you ever wondered what makes people happy? Besides love and loved ones, of course. Probably your first thought will be money. It’s well known that money can’t buy happiness, but it sure can make life more enjoyable. Being able to provide for one’s basic needs and having the flexibility to pursue meaningful activities that bring us joy – whether it be going on a dream vacation, taking up a hobby or helping a loved one out financially – contributes greatly to our overall wellbeing. Of course, the lack of money affects the feeling of happiness. However, there are other sources of happiness that do not depend on money. They are health, longevity, freedom of choice of occupation, freedom of pastime, a sense of shoulder from the government and leadership, a favorable environment, and much more. When it comes to governments taking care of the happiness of their citizens, there

The COVID-19 pandemic has had a massive impact on our daily lives. It’s changed the way we work, play, and interact with each other. People are now more accustomed to social distancing, working remotely, and wearing masks whenever they’re in public. Businesses have been affected as well – many of them now completely rely on digital solutions to stay afloat. Education has also taken a hit; with venues switching their entire curriculums over to virtual platforms almost overnight. We’ve seen dramatic changes across all aspects of life – from transportation shutdowns to canceled events – that have together created an unprecedented disruption worldwide. The first wave of covids-19 seriously affected the world economy because the world was not prepared for a pandemic. This led to an increase in cases, deaths, unemployment and poverty, resulting in an economic downturn. The situation was exacerbated by the fact that in addition to the

Life expectancy is a complex measure that’s affected by many different factors. Genetics, lifestyle choices, access to healthcare, and even geographical location can all play a role in how long the average person can expect to live. Water quality can have a huge impact on mortality rates, as it largely affects whether an area experiences outbreaks of waterborne diseases such as cholera, dysentery and typhoid. Poor water quality can lead to long-term health problems for those living in the contaminated areas too, with individuals consuming large quantities of water providing harmful contaminants over time. Water contaminants have also been linked to cancers such as bladder and stomach cancer, increasing the risk of mortality if left untreated. Generally speaking, access to safe drinking water is essential for a healthy lifestyle and it’s imperative to regularly monitor and update our infrastructure so everyone can feel safe when accessing their clean drinking water

Apple iPhone smartphones are undoubtedly the product of the decade. According to estimates by Strategy Analytics, Apple shipped 1.2 billion devices worldwide between 2010 and 2020, earning about $760 billion! What’s even more amazing is the continued crazy demand for these phones over the years. There is huge competition among smartphone brands in the market today, where you can get a smartphone with the latest technology at half the price of an iPhone. Nevertheless, even after decades, these smartphones are extremely popular and iPhone sales worldwide are high. Of course it would be very interesting to analyze Apple’s sales data. To see which models sell better and which sell worse and to understand why. However, finding the necessary data for this analysis turned out to be a difficult task. Mostly there are either tables with general sales data or very old data from 7-8 years ago. I could only find

Every modern bank can be compared to a huge analytical machine. Banks store and process enormous amounts of information. They know everything about people’s income, their property, their priorities. And they have such information not only about their borrowers, but also about those who have already taken loans from other banks. Banking analytics is a powerful tool for modern banks to make data-driven decisions and provide great customer service. By collecting, analyzing and interpreting large amounts of financial data, banks can gain valuable insights about their customers’ needs and trends in the banking industry. They can then use this information to develop more efficient products and services, create better user experiences, reduce fraud and improve risk management. With the help of this technology, banks can make smart and timely decisions that improve their operations while keeping up with the ever-changing world. Analyzing banking data is always interesting. I always discover

Is high pay synonymous with happiness? More likely no than yes. The U.S. is (so far) the richest country in the world, but people there are less happy than in many other, more modest countries. Sweden, for example. People in Sweden are generally more content than those in the US for a number of reasons. For starters, Swedes enjoy higher levels of paid vacation and parental leave; plus, most people there have access to affordable healthcare and education services. On top of that, Swedes tend to be more trusting of each other — and their government — which creates a sense of security and community that’s just not as evident in the US. Also, Swedish culture emphasizes prioritizing family time and leisure pursuits over professional obligations, so people are better able to achieve balance between their personal lives and careers. In contrast, many Americans grapple with longer work hours, stagnant

Gambling. Slot machines. Easy money. Many people dream of getting rich through gambling. But for some reason they do not succeed. Who really makes good money in gambling are the owners of casinos and slot machines. Because all casinos, lotteries, slot machines are set up in such a way that they always win in the end. That is because all the algorithms inside them are not genuinely honest and have a shifted mathematical expectation. Take, for example, slot machines. Yes, a player can win playing slots, and even very well – 200 dollars per 1 invested dollar. However, the probability of this event is extremely small. And to make this probability happen, the player needs to make hundreds and thousands of attempts, spending his dollars each time. As a result, the player simply goes bankrupt faster than the casino. And never got to his coveted $ 200. Or achieved, but

I think it’s no secret that the younger generation is now searching job by completely different factors than people who are in their 30s or 40s. Surprisingly, for many people of Generation Z the importance of the salary factor is lower than, for example, the ability to work remotely. In addition to remote work opportunities for young guys and girls, it’s important to be a part of the company’s mission, social contribution, active mentoring by supervisors, and many other factors. And it is advisable for employers to consider all of these factors even before the job is posted and interviews take place. Career aspirations analysis is an important step in any professional’s path to success. It involves examining candidate current skills and interests, as well as looking at future trends in order to determine which career would be the most suitable and fulfilling for future worker. This may involve researching

The mobile development market has been booming in recent years. That’s because people all over the world spend more and more time with their smartphones than with their computers. It is not surprising that many developers of websites, programs and games have switched their attention to mobile development for Android and iOS. It seems much easier for them to create there a popular app and get rich. It would seem that here it is a growing market, take it and do it. To be honest, it seemed that way to me, too. Until I did this research. Yes, of course, both the App Store for iOS and the Play Market for Android are growing markets. And the latter is growing even faster. Google Play Market contains a vast library of apps, making it easy for users to find whatever they need for their device. On Google Play Market, you can

Today Google is the largest search engine in the world. This website is where most of the world’s people enter the Internet and search for the sites they need. According to the company’s executives, 76% of all Internet searches in the world start with Google. Google is also an amazingly complex product. Not only do its servers store vast amounts of data about billions of web pages, but they also analyze user behavior on them. That is, they literally watch every move billions of people make! The scale of this search giant is impressive. Just think about it: approximately 3.5 billion searches are performed on Google daily, which means that approximately 40,000 searches are performed every second on Google. Every second! Of course, Google knows about all the search queries people enter. And that information is extremely valuable. The company itself is reluctant to share this data. Certainly, there are

Today, there is probably no person on Earth who has not tried to play computer games at least once. Meanwhile, even until the early 2000s, it was predominantly a niche market focused on children and teenagers. The videogames market has experienced incredible growth in recent years, with the development of more advanced gaming systems and a whole range of games aimed at entertaining players. This has also led to an increase in the number of casual gamers, as playing is no longer restricted to hardcore gamers or expensive consoles. Mobile gaming, for example, has enabled a massive expansion of the market by making video games more affordable and accessible than ever before. Thanks to advances in app technology and cloud-gaming platforms that are available across multiple devices, people from all walks of life can now enjoy a variety of games that was previously unavailable to them. Developers have responded by