Stefan Pisjak

1st website

One day outside of school I started playing around a bit with HTML, CSS and jQuery. A few tutorials later, I had my dynDNS, Apache2 and my static site hosted. Which was reachable from everywhere on the internet, what blew my mind back then.

This is the link to the Github repo. But over the years I moved from Apache2 to nginx and started to use CSS preprocessors, such as SCSS or Sass.

Android Apps

Pretty much just after learning the basics of programming in Java I decided to write an app. And of course, the first thing to try out, was a counter, with an increment and decrement button. Eventually the decrement button had to got, and I created yet another clicker app, with automatic clicking and whatnot.

Either way, I had some fun messing around with Java and the Google Play Console and finally sharing them with my friends on Google Play. In the meantime they are already removed from the Play Store again, as the targeted Android version is too old, but repos for Schober Clicker (this clicker app), Schober Life (inspired by Reigns), Schober Orakle (inspired by The Magic Shell) and Schober Calculator (a very basic calculator) do still exist.

But don't take it as a ref for my coding style, at this point I didn't even know yet, what a constructor is, and wrote my own init functions to initialize my objects xD Still I enjoyed those projects a lot

3D modeling & animation

In late 2019 I then decided, that I wanted to mess around with Blender. In this time period I learned a lot about modeling (especially for performant/low poly objects for games), texturing and animation.

I did a lot of minor animations, such as animating how Quicksort works (this animation is unfortunately lost to time). One day I felt the desire to model something bigger, so I asked a friend, what I should create. This resulted in a 3D model of the Panzer IV Aus. H.

Arch Linux

At this point, I have played around with some Linux distros and tried to use them as my daily driver. And I used Manjaro for a while, but I was sick of being stuck with "2 weeks old packages" [citation needed] and wanted to customize every bit of my OS. Also, I just needed a new challenge, so Arch Linux it is ( + i3 as WM ).

Currently (2024) I am using a combination of Arch Linux with Sway and Ubuntu with i3 for work. My dotfiles can be found here in case you are interested ;)

Server + Docker

In mid-2020, I started my journey into the world of self-hosting. I had already hosted my own website for quite a while, but after I learned about Docker/Containers and how easy it is to separate indented workloads, I was instantly mesmerized.

I invested in some hard drives and SSDs and set up a RAID with LVM with SSD cache on top. Everything I found useful was self-hosted, from Home Assistant to Nextcloud or Photoprism (there are like 50 more, but I will stick to the highlights). I also had some fun with nginx and Traefik as a reverse proxy, as well as the cert boot for my certs from Let's Encrypt.

Godot

After doing a lot of operational stuff, I decided, that it was time to develop again. I created a few games in Godot, the most noteworthy being YASH, which I created together with lumi200. This brought the table-top game Secret Hitler to all devices, from mobile to desktop to even consoles. It was quite fun working on the networking stack of the game.

Some more Android

As the stars realigned, I was working again on some Android apps again. For a while I played a bit around with Dart and Flutter. But eventually I created a new app (in the same weird naming scheme as YASH before) called YAU (YetAnotherUntis).

This app allowed the user (mostly me and some friends) to sync the school calendar to the local Android calendar instead of opening a dedicated app every time you want to know if the next lession is held or not. It was quite a ride, because I learned a lot about how to keep your app running in the background as well how to interface with the Android Accounts/Calendar/... Also I decided to give Kotlin a try this time.

Commean

Together with lumi200 once again we worked on our diploma thesis Commean. The crux of it was that we analyzed traffic flow within a city to know where people wanted to go and help people shape better public transport.

I worked on recognizing vehicles on a single board computer called Khadas VIM3 (basically a Raspberry Pi with Neural Processing Unit [NPU]). I played around with a few neural networks, such as YOLOv3 or SSD. Eventually I chose YOLOv3, as it produced better results. Unfortunately the NPU was not fast enough to produce a high enough frame rate to easily map vehicles between frames. Therefore, I used different approaches to relate vehicles from frame to frame, such as feature matching or optical flow (I really found a love for computer vision there).

The results then had to be sent to our central server via LoRaWAN. So I created a PCB for our chip and then had to port a library (LMIC to interface with our LoRaWAN chip to the VIM3. Then I used ZeroMQ to interface between both programs and had some fun writing my SystemD modules to start everything automatically on startup. I also created our Homepage in Vue.js and had fun with some animations using anime.js.

Both our backend (Java/Spring) and frontend (Vue.js) was written by lumi200. I won't get into detail here, but he also had his fair share of fun with The Things Network and time series databases. Together we won some national prices and had a fun time :) Be sure to check out our thesis (written in Latex, repo can be found here) for way more details than I can put in this "short" summary.

Rust & Git

After Commean and during my civilian service, I sought some smaller projects. Also, I finally wanted a unified process to tag all my images using the GitLab CI or any other CI. It started out as a little shell script in the Android Rom Builder (a little tool to help build custom ROMs with containers). But I quickly found out that I didn't want to depend on Git being installed in the container that builds the image. Also, it was the perfect opportunity to test out Rust.

So, using the libgit2 C library (git2 crate), I played a bit around and had fun rev-parsing around and getting to learn Git in more detail. This finally resulted in VIT (Version IT!).

Kubernetes & Monitoring

Up to this point, I still have been using my Docker containers running on my server. But I decided, that this was not enough and started using k3s to provision my workloads. Also, I set up alerting and monitoring with Grafana, Loki and Mimir/Prometheus. And I fell in love with the idea of GitOps. I guess I already did something similar with my docker-compose.yamls before, but now it's self-healing with ArgoCD. My workloads are also maintained by using the Renovate Runner.

My workloads can be found on GitLab as well.