Spider web with droplets of water representing the social bubles
Spider web with droplets of water representing the social bubles

What is Polarization?

Polarization describes the division of people into two contrasting groups or sets of opinions or beliefs. The term is used in various domains such as politics and social studies. For example political polarization refers to the divergence of political attitudes to ideological extremes. Social studies use this term to describe the segregation within a society in terms of income inequality or social and class status.

Currently social media are one the biggest sources for news and information as more and more people go online to discuss and socialize. …


The serverless architecture provides services on demand. Well, servers are still used but a company is charged from the cloud vendor only on its usage and not for a fixed amount of servers. This happens by triggering them to work only when needed. These services are auto-scalling and cut a lot of daily costs and deployment time.

Nowadays we use modular separate components to build an application. This is known as the microservice architecture.

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Function as a Service?

Function as a service is a serverless way to execute modular pieces of code. …

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Photo by Julie Kwak on Unsplash

Synchronous requests are easy to read and debug. The thread freezes until you get a response back. You handle errors and that’s it.

The thing is that we want users to continue interacting with the application while the program waits to get a response back. The error handling and debugging becomes a bit more complicated.

In our case we can leave all this handling to Picasso, a powerful image downloading and caching library for Android.

Suppose that we have a custom preference category for the settings of my application with various sub sections.

Now as we can see above…

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Let’s say that we have a missile travelling. The missile is using sensors to determine its position. The sensor data are stored in matrices. Every new, for example, nanosecond a new reading from the sensor arrives. It is really expensive to recompute the whole matrix of the readings for calibrations and other operations.

When the right-hand side of linear system changes but the matrix stays the same, then an LU factorization is needed to avoid computing the whole system again.

But what if the matrix changes?

It is possible to avoid refactoring even with a change in the matrix. For example, making a “Rank-one update”. …

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Photograph by Maël Ball

People just hate javascript to fit in, to look cool or to sound like they know what they’re talking about. This issue is one amongst many arguments that make the “JS bad”.

Javascript depends on npm packages. As we can see in this issue this utility function, whose sole purpose is to return a boolean value, according to naming conventions, does not always return a boolean value.

We can see at the dependency graph that nearly 3.4 million repositories were affected. This is the one-liner that did the job.

Pretty unreadable, amirite? If you write it out in long…

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Photograph by Laura Stanley

R-trees? More like B-trees on steroids

R-trees are tree data structures used for spatial access methods, i.e., for indexing multi-dimensional information such as geographical coordinates, rectangles or polygons.

Spatial data

An object is characterized as spatial if it has at least one attribute that captures its location in a 2D or 3D space. Moreover a spatial object is likely to have geometric extent in space. For example, we can say that a building is a spatial object, since it has a location and a geometric extent in a 2D or 3D map.

There is no total ordering in the multidimensional space that preserves spatial proximity. As a result…

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Photograph by Timo Volz

What is a computer network?

A set of two or more computers that are connected between them with one or more physical means.

Every computer is called a node, a node of the network can be any kind of computer or a terminal. Every node is defined by at least one alphanumerical value that is called an address.

A physical mean is called a link, channel or couple. For example, optical fibers or coaxial cables.

The nodes and links make up the resources of the entire network.

Point-to-point and Full Mesh

The simplest way to connect is a direct link between two nodes. Now if we have N nodes…

The study of facility location problems (FLP), also known as location analysis, is a branch of operations research and computational geometry concerned with the optimal placement of facilities to minimize transportation costs while considering factors like avoiding placing hazardous materials near housing, and competitors’ facilities.

Consider the following scenario

A rural area of a country has decided to improve their health and medicine access. They decided to build a new hospital and a pharmacy but everyone argues about the optimal location of these facilities. Some argue about the population of the cities and others about the distance.

The first step…

In this post we’ll get through the process of creating a search engine app with Angular. We will check out how solr works and the simplest way to configure our index based on our dataset.

You can browse the code of the project while reading through this blog HERE.

Let’s start by defining all the slang we need to know.

What is an index?

An index is a list of data. It is typically saved in plain text so that can be quickly accessed by a search algorithm. This significantly speeds up searching. …


Data visualisation is used to display data in a way that one can identify patterns and relationships between them. In this article i will explain how i created an application that creates timeline, bar and scatter graphs from the Gapminder dataset.

Note: The point of the article is not to explain how to create an angular app and how the angular framework works but to display the approach i took during the development of this project.

You can browse the code of the project while reading through this blog HERE.

Designing the database

Database design is the organization of data according to a…

Leonidas Boutsikaris

Software Engineer, writing code and blogging about it. Found something interesting? Buy me a coffee! https://ko-fi.com/leobouts

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