A picture from Mozilla Festival 2014. All participants are in a circle.


I'm Errietta Kostala (or Erry) and I'm a full stack developer...

with a passion.

Learn more

Ever since I was a teenager, I knew I wanted to be involved in programming. I spent countless hours working on my own projects, learning more and more and becoming more and more fascinated.

As I started getting involved in freenode, Mozilla, and other open source projects, it became a way to be part of a community - I could network, make friends, and meet people that would be with me for the rest of my life.

It then became clear to me - I didn't just want to follow my passion of programming. I wanted to teach others what I knew. And I wanted to keep supporting Open Source projects and helping others.

For this reason, I studied Web Technologies at the University of Huddersfield - so that I can learn even more about what I'm passionate for, and I did an internship for Shadowcat Systems - a small company in Lancaster that holds open source and community projects very dearly.

Do you want to learn more about me? Check out my projects or my blog .

Latest blog posts

How to get the best job offer for senior+ software engineer roles

Originally published on dev.to Navigating “senior+” job interviews I recently did a round of job interviews. I’m on the top end of the Senior Software Engineer band, and I was looking for other “top of senior” or Staff Software Engineer roles. At the end of the interview process I had two continue reading...

The post How to get the best job offer for senior+ software engineer roles first appeared on Errietta (Erry)'s blog ☕.

How I solved github’s actions capture the flag challenge

Introduction First of all, I’m aware it’s April 1st, I was thinking of some joke post but then I remembered that I have an actual serious post I’d like to write, so this is not any kind of joke. The challenge & repo A while back, Github posted a capture continue reading...

The post How I solved github’s actions capture the flag challenge first appeared on Errietta (Erry)'s blog ☕.

Python argparse cheat sheet

I have a confession to make: I never remember how to use argparse. Maybe it’s because I don’t use it often enough to have how it works memorized, but I certainly use it often enough that I’m annoyed every time I have to look it up. Argparse? More like ARGHparse. continue reading...

The post Python argparse cheat sheet first appeared on Errietta (Erry)'s blog ☕.


I have a sneaking suspicion Errietta is going to be scary good in a few years.

Matt Trout, Shadowcat Systems Technical Director.

We get a lot of contributors but it is not every day someone so seamlessly integrates with the entire team. I went away on vacation and when I came back Errietta was an integral part of our work environment – a powerful presence on IRC, at our video demo call and on GitHub.

Cassie McDaniel, Webmaker UX Lead

Errietta has all the qualities of a great web developer — learns quickly, values feedback from both engineers and designers, and cares deeply about sharing knowledge with others. I'm always impressed by how quickly Errietta is willing to jump into a new code base and effectively solve problems.

Kate Hudson, Webmaker Developer