Yukihiro Matsumoto, the creator of Ruby programming language, famously said: “I hope to see Ruby help every programmer in the world to be productive, and to enjoy programming, and to be happy.” Honestly, not many programming languages were built with developer’s happines in mind. And to be honest, Ruby is a joy to work with. It’s fairly easy to learn, easy to read, yet, very powerful. Also, with the appearance of Ruby on Rails, it became insanely productive. But first things first. Read...

Border Gateway Protocol, BGP for short, is probably the most important protocols you might have never heard of. Well, you did at least once, in October 2021. When Facebook, WhatsApp, Instagram and Messenger all went down because of BGP misconfiguration. Or that one day back in 2008 when all YouTube traffic was accidentally routed to Pakistan. Because of BGP… misconfiguration. So what’s the big deal with BGP? First we must understand how the Internet works. Read more:...

SQLite is by far the most common SQL database ever deployed. Are you lsitening to this on iPhone or Android device? It runs SQLite. Or maybe through a web browser? Chrome, Safari, Firefox, Opera and Android Browser all use SQLite underneath. Are you running MacOS or Windows? It’s built-in. Most Linux distributions have it as well. “But I’m listening to your podcast while driving a car”, you say. Well, most automotive systems use SQLite internally. If you happen to listen to my podcast while...

Scala is a programming language running on the Java Virtual Machine. It’s statically typed, and you can use it both as functional and object-oriented language. Even at the same time. The functional side of Scala supports higher-order (and higher-kinded) types. For those of you know what it means. On the other hand, object-relational features of Scala are equally strong. Including powerful trait composition, that you can somewhat compare to multiple inheritance. Combine than with great Java...

K-means clustering is an algorithm for partitioning data into multiple, non-overlapping buckets. For example, if you have a bunch of points in two-dimensional space, this algorithm can easily find concentrated clusters of points. To be honest, that’s quite a simple task for humans. Just plot all the points on a piece of paper and find areas with higher density. For example, most of the points are located on the top-left of the plane, some at the bottom and a few at the centre-right. However,...

Clojure is a dynamically, strongly typed programming language. It’s a dialect of Lisp running on the Java Virtual Machine. Lisp is 6 decades old and has a really weird syntax. That weird syntax is called Polish prefix notation. Basically, in every other language you’ve used math operators like plus or minus are infix. It means they are placed between operands. For example, 1 + 2. In Clojure, you always put the operator (or any other function for that matter) in front. So simple addition...

There are two main ways to communicate between components in your distributed system: synchronous and asynchronous. Synchronous communication is like making a phone call. The system on the other side must be present and you actively wait for a response to your every question. Examples of this style include REST, SOAP and GraphQL. Read more: https://nurkiewicz.com/91 Get the new episode straight to your mailbox: https://nurkiewicz.com/newsletter

After many dramatic events around Twitter lately, many people, including myself, began experimenting with Mastodon. Superficially it’s an open-source clone of the former that anyone can deploy and host. However, once you look deeper, it’s actually a completely different philosophy and architecture. Let’s focus on how Mastodon federated network is built. To understand the difference, we’ll start from scratch. Read more: https://nurkiewicz.com/90 Get the new episode straight to your mailbox:...

RabbitMQ is a message broker, allowing asynchronous communication in distrubuted systems. The key advantages of RabbitMQ include: 15 years of open source history, battle proven Erlang implementation and support for industry standard protocols. RabbitMQ is among the most popular implementations of message brokers. Others include ActiveMQ for Java, celery for Python and Kafka - if you consider it a message broker. Also, pretty much all cloud providers have their proprietary implementations,...

Many people, when asked about SLA, simply shout 99%. The correct answer to that question is probably a long, boring PDF, written by lawyers. Yes, SLA is a legal obligation. Not a metric or a number. You probably meant SLI or SLO. Read more: https://nurkiewicz.com/88 Get the new episode straight to your mailbox: https://nurkiewicz.com/newsletter

An artificial neural network is a computer algorithm somewhat inspired by our brains. Superficially, our brain is a network of neurons connected with each other and communicating via electrical impulses. Artificial intelligence experts implemented a similar concept purely in software. An artificial neuron is basically a function that takes a set of inputs and has an output. Just like the biological one. By connecting hundreds of such neurons in a network, we can observe quite intelligent...

p>A few weeks ago Ethereum blockchain moved from proof-of-work to a proof-of-stake algorithm. This step alone reduced global energy consumption by 0.2%. It’s as much as an energy usage of Austria. At this point, Ethereum, the second largest blockchain after Bitcoin, is using barely as much electricity as a few hundred households. How is that possible? How does the proof-of-stake algorithm work, avoiding catastrophic energy waste? Read more: https://nurkiewicz.com/86 Get the new episode...

A genetic algorithm is a heuristic approach to solving complex computational problems. This includes various optimizations, especially around scheduling and design. For example, NASA designed a radio antenna for their spacecraft using a genetic algorithm. Its shape is quite complicated, like nothing that could be designed by hand. So how do genetic algorithms work their way to the solution? Well, they are inspired by the natural selection process in living creatures (!) Read more:...

Non-fungible tokens, NFTs for short, are financial instruments implemented on top of the blockchain. They can be bought and sold, just like cryptocurrencies. However, unlike bitcoins, each NFT is unique and traded individually. Whereas Bitcoins or ether are interchangeable, just like hundred-dollar bills. So what makes each NFT unique? Why would you purchase this particular NFT rather than the other one? Well, an NFT has an associated piece of data. That data is typically a hyperlink to...

We all know this feeling. You search for a hotel in Paris and you keep getting ads for hotels and flights for weeks to come. Or something even scarier. You visit a blog post highlighting the first symptoms of a pregnancy. An hour later every single website on the planet advertises diapers and baby formulas. How is that possible? How do they know? And how did we get into this dystopia? All of this became possible with real-time bidding. The billion-dollar industry that tracks our...

MongoDB is a NoSQL database. Precisey speaking, it’s a document-oriented database. It stores arbitrarily complex key-value objects. For example, in a single Car object you can store as much information as you want. Not only license plate or manufacturing year. But also information about each individual part, history of repairs, insurance and all owners. No matter how much information you want to keep, you just put that in a single, easily accessible document. Contrast that to relational...

Quarkus is supersonic, subatomic Java. What does that mean? It means it’s Java, but really, really small. And really, really fast. Quarkus is a runtime framework which gives you access to programming models you’re probably familiar with. Like Microprofile, JAX-RS, CDI dependency injection. And also access you’re probably less familiar with, like reactive programming. Author: Holly Cummins Read more: https://nurkiewicz.com/81 Get the new episode straight to your mailbox:...

Ethereum is a network of computers with no central trusted authority. They achieve consensus by running computation-intensive algorithm, known as proof-of-work. The agreed state is added to an append only ledger, known as blockchain. Yes, Ethereum is yet another blockchain. And it’s used to track transactions in a cryptocurrency, known as Ether. However, unlike Bitcoin, it’s much more than a simple log. Bitcoin accounts simply hold currency. Ethereum accounts can run programs as...

QUIC can be thought of as the third fundamental protocol of the Internet. Next to UDP and TCP/IP. Let’s talk a little bit about these two. They both build upon IP, Internet Protocol. IP supports exchanging packets of data between two machines having… IP addresses. UDP adds ports. Port is a logical concept. It’s simply a number within one machine that identifies a certain process. Thanks to ports, many different processes on the same machine can exchange data. Read more:...

Stuxnet was probably one of the most sophisticated pieces of software ever built. I can easily imagine a Hollywood movie about it. A computer program that could change the course of history. Ironically, Stuxnet was a computer virus. A virus that infected 200 thousand machines. But activated and damaged only on a fraction of that. Read more: https://nurkiewicz.com/78 Get the new episode straight to your mailbox: https://nurkiewicz.com/newsletter

Denial-of-service attack tries to take down a server by sending specially-crafted requests. The simplest form of this attack is just sending a lot of requests in a short period of time. But more sophisticated methods are possible. For example, sending a single unusual request that overwhelms the server. One such example is a ZIP bomb, that I’ll explain later. But the most widespread technique requires a large number of attacking servers. Also known as distributed denial-of-service. DDoS for...

In part 2 of the Twelve-Factor App, we’ll explore the second half of the principles. Be sure to listen to the previous episode as well. We still have only four minutes, so let’s go! Read more: https://nurkiewicz.com/76 Get the new episode straight to your mailbox: https://nurkiewicz.com/newsletter

Twelve-Factor App is a set of design guidelines defined by Heroku. These guidelines are best suited for cloud-native, portable and resilient services. In this episode, I’ll explain the first seven principles. I have four minutes left, so let’s go! Read more: https://nurkiewicz.com/75 Get the new episode straight to your mailbox: https://nurkiewicz.com/newsletter

SOAP, formerly known as Simple Object Access Protocol, is a messaging standard. SOAP is very broad and general. Technically, it can support request-response, as well as fire-and-forget communication. The underlying protocol is typically HTTP, but there’s nothing against using message brokers. Or even good old SMTP. You know, the one for exchanging e-mails. The communication happens through XML messages. These messages are well-defined and structured. XML schema is agreed upon before...