Jannik Arndt

After six weeks in Palermo, these are the words and phrases I use almost every day.

The first two weeks of my two months in Palermo are almost over, and I learned a lot.

I left the cold and dark Hamburg winter and escaped to Palermo for two months.

This week we woke up to customer reports that they couldn’t reach their “Public Portal” (a way to share their roadmap) anymore.

Over the past year, many (including me) have left the company I worked for for more or less growth-related reasons.

Update, 2026: Apple released a native Charts framework at WWDC 2022.

…in my experience.

Scala traits should define defs, because “A val can override a def, but a def cannot override a val” (via Alvin Alexander via StackOverflow).

We recently had another team rewrite their service in Rust, with a massive boost in performance.

Do you know what happens after you compile?

I recently created a wonderful bug.

This is a basic example how to implement oAuth2 using Akka HTTP and Scala.

Getting a Akka HTTP-based backend up and running on Heroku for free can be done in less then 30 minutes — if you know the tricks.

This example show how to write a reactive reader for the AWS Simple Queue Service, using Scala and alpakka (respective akka streams).

While the Akka documentation is incredibly well written, it has surprisingly few images.

Changing the password for a PostgreSQL database user involves two steps: The change in the database and the change in the application code.

The PostgreSQL installation comes with a great tool, psql, to administer and inspect the database. pgcli extends this with syntax highlighting and autocompletion.

I want my photos to have location info in them, and Nikon wants way too much money for that.

You don’t need to “get hacked” to have your security compromised.

Adding an ssh-file as a secret sounds easy, but there are pitfalls.

I reduced the startup time of my shell by one second.

Apples Time Machine is a great backup solution, you only have to do one thing: Connect your disk from time to time.

Update, 2026: The SonOTA flashing method described here is deprecated.

Update, 2026: Apple’s Home architecture has changed significantly since 2018.

I bought a raspberry pi as a smart home automation server.

This is a quickstart for building something on Google Compute Engine without clicking any buttons (after you created the project).

#1 Conway’s Law “organizations which design systems … are constrained to produce designs which are copies of the communication structures of these organizations.”

I was quite surprised at how difficult it is to get absolutely razor sharp images out of a very good (high-end-consumer/semi-pro) DSLR camera, namely the Nikon D7100.

If you write Scala in a Java-centric environment, chances are you might wind up with a Maven project, defined in a pom.xml.

Storing case classes in a MongoDB database is incredibly easy, once you know how.

This post contains the absolut essence from the Terraform Getting Started Guide: https://www.terraform.io/intro/getting-started/install.html

Ever wondered where bad code comes from?

Some ideas seem great at first but turn out to be incredibly bad in hindsight.

I tried to create a single image that contains all the most important git commands:

Last week one of our programs failed looking up an airplane by its registration.

TL;DR: You don’t.

My favourite animal: The Beluga!

Task You have a denormalized table and want to extract a column into a dimension table.

#1 Do not fix your code.

Being the IT-guy aka personal first-level-support™ for way more people than I am comfortable with, I have held quite a few mobile phones in my hand and stared into the abyss that is their home screen.

(via I Love Programming) Thank goodness, we don’t do production.