Analyzing the performance difference between the JVM frameworks through benchmarks — The question “Why Spring is faster than Vert.x?” in its different variations is being asked on StackOverflow once a month on average. After all, Spring is still the most popular JVM framework by far, so lots of companies use it. But Spring Framework isn’t known for its performance. Vert.x, on…

In May 2021, I was endorsed by Tech Nation as an Exceptional Talent and received Talent Visa from the UK government. I want to document my year-long journey in hopes that it will help others with a similar background. This will be a long one. Talent Visa is intended for…

At Depop we utilise PostgreSQL in most of our microservices. In addition to common data types, such as integers, floats and strings, PostgreSQL also supports array data types and has a whole set of functions that operate on them. Here’s just one of the problems those capabilities helped us solve. …

So, you develop some of your services with Kotlin and Ktor. Normally, your Ktor services will sit safely behind a reverse proxy, that will handle all the basic security concerns, including SSL, for you. And in your test environment, you would be running without SSL at all, simply bypassing all…

One of the main features of Go programming language is its eponymous go statement. In my opinion, though, the go statement is one of its main drawbacks too. And that’s not only me. Unlike expressions, statements don’t bear any result. In Go, it’s super-easy to start a new goroutine. But…

A few weeks ago my friend Dmitry Karlinsky wrote an article about “Demystifying functional effect systems in Scala”, which was a fascinating read. In less that fifty lines of code Dmitry has built an IO Monad, similar to what users of ZIO/Cats-Effect/Monix are familiar with. This article prompted me to…

On 16th of June the Go team has published an update on generics in Go. Alongside a very thorough design draft, that ditches “contracts” and adopts more conventional approach to typed parameters, came the ability to play with generics yourself online, using the new Go Playground. Let’s see how to…

A few days ago Ron Pressler published article called “State of Loom”, which was endorsed by all the greatest people of JVM community, for all the good reasons. While an interesting read by itself (I personally liked the “taxi” metaphor a lot), I was skeptical how useful this solution could…

Lately I’ve stumbled upon an interesting task — executing a function exactly once, while invoked from multiple coroutines. That is, having: fun compute() { println("Computing") return 1 } Invoking: for (i in 1..10) { launch { println(compute()) } } Should print “Computing” once only. What are our options? First, let’s…