Igor Šarčević — @shiroyasha

Software engineer at Rendered Text / SemaphoreCI.

Hi there!

Welcome to my personal blog, a space where I like to share updates, tips, tricks, and events I take place in.

My name is Igor, but many people know me by my handle @shiroyasha. I’m a software engineer, working at Rendered Text, the company that creates SemaphoreCI, the leading continuous delivery platform focused on speed and simplicity.

I enjoy everything that is connected to shipping and maintaining a great product. Writing code, setting up the infrastructure, promoting the product, giving technical talks, drawing, writing, teaching, doing customer support… I enjoy every part and every role.


I am most skilled with writing Rails based software by following BDD principles, but I have developed solid skills in other areas as well. Instead of sharing a list of technologies, I’ll share the list of major features that I implemented on Semaphore.

  • The first major feature I shipped was the introduction of interactive SSH sessions into our build machines. From the UI, through virtual machines, down to firewall settings.

  • Software that orchestrates virtual machines. Starting, stopping, and preparing clean build environments for every CI job executed on Semaphore.

  • I was part of a small team that wrote our first microservice 3 years ago. The start of our effort to break our monolith into small, dedicated components.

  • I laid the foundations of our AWS infrastructure, introducing Docker as our primary software delivery mechanism. This infrastructure has ever since supported our rapid microservice growth without any bottleneck. In the process we created Alpine Release, our standard Elixir packaging tool.

  • Introduced RabbitMQ as our official service communication channel. Creating Tackle and ExTackle along the way.

  • Wrote 2 out of the 10 most popular technical articles on Semaphore’s community. Both articles tackle the issue of continuously testing your JavaScript applications.

  • Last year, I lead the team that completely rewrote our Build and Deploy scheduler, a piece of software that is responsible creating, scheduling, assigning build machines, and collecting results of every CI job that is created on Semaphore. A rewrite that allowed us support for 10x higher job throughput, and single builds that could be parallelized across more than 100 build machines.

Personal Life

I was raised in a small town in Serbia, but I didn’t know Serbian until I turned eight years old. Until then I only spoke my mother thong — Hungarian. Raised in dual language environment sparked my love for languages, and currently I speak four: English, Hungarian, Serbian and Japanese.

Japanese is probably the most outstanding on the list, a language which I started learning while watching anime and reading manga, but continued with dedicated Japanese classes at the first year of university.

I always enjoyed doing martial arts. It is the best way to learn discipline and to gain the necessary mental toughness to handle hard kicks that life can sometimes serve you. I was involved with some kind of martial arts from when I was only five years old, but I only took martial arts more seriously when I turned twenty.

I started with karate, but I slowly transitioned to Ninjutsu, and tried out various others like Kendo and Aikido.

Besides martial arts, I also enjoy hiking, jogging and swimming.

How can you contact me?

I enjoy dark, locally brewed beer. If you are from Novi Sad feel free to invite me to one of our local places for a pint or two.

You can also find me on: