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 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'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's blog ☕.

Documenting a Django API with OpenAPI and Dataclasses

Django makes it easy to quickly spin up APIs and provides a great admin interface and command line management tools. It certainly speeds up the development of any CRUD system. However, as your project grows, you will want to make sure your code is well-documented, both for your backend developers continue reading...

The post Documenting a Django API with OpenAPI and Dataclasses first appeared on Errietta'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