Hi.

I'm Markus, a software engineer apprentice at HolidayCheck.

Latest stories

MMy last station

07/24/20191 Min Read — In BusinessPhase

The last two weeks of my business phase have started, and since Monday I am again in a new (and also my last) team. This team is responsible for HolidayCheck Reisen, and I was also involved in the…

RRefactoring Techniques

07/18/20191 Min Read — In Refactoring

Currently, I'm reading the 3rd chapter of Martin Fowler's book Refactoring: Improving the Design of Existing Code. So far, I like the book and the examples Martin Fowler provides. However, sometimes…

AAnother week in the Business Phase

07/12/20192 Min Read — In BusinessPhase

This week I joined a company which differs from what I've seen so far in the business phase. A Company? Yeah, the car rental portal Driveboo which is a full subsidiary of the HolidayCheck Group AG and…

HHalftime

07/02/20193 Min Read — In Apprenticeship

It's the beginning of July, which means that half of my apprenticeship time is already over. This post is all about my time here at HolidayCheck, how I got here, what I've learned, and how it proceeds…

DDocker Basic Commands

06/27/20191 Min Read — In Tools, Docker

These days I setup a CI-Server using Jenkins and Docker. I decided to go with Docker since I didn't want to 'pollute' my local machine further 😅. Another reason for using Docker is that the setup is…

OOption vs Either (Part 3)

06/26/20193 Min Read — In SoftwareDesign, Refactoring

This post is the last one of the Option vs Either trilogy. In the first post, I introduced the Option type and why it should be used over null. In the second post, I introduced the Either type and…

OOption vs Either (Part 2)

06/24/20192 Min Read — In SoftwareDesign

In the first post of this trilogy, I introduced Scala's Option type and why I prefer it over null. This post is all about another Scala monad called Either. Motivation Let's build a little wheel of…

RRSS Feed works

06/24/20191 Min Read — In Blog

This post is just a test post to check if RSS Feed / Slackbot integration works.. :-)

OOption vs Either (Part 1)

06/20/20191 Min Read — In SoftwareDesign

The last days I paired with Lewis, a former apprentice, to refactor some functions in a Scala codebase. By doing this, we decided to refactor the return type of some functions from Option to Either…

OOn 'Transformation Priority Premise'

06/12/20192 Min Read — In TDD

A few days ago I read an article by Uncle Bob entitled Transformation Priority Premise. This post summarizes it's core idea of Transformations and the Transformation Priority Premise. What is a…

BBusiness Phase - Get to know the Urlauber

06/06/20191 Min Read — In BusinessPhase

My last post was already a few days ago, which is because I am now in the business phase. This and next week I am in the department Service&Complaints, so I have a lot of contact with the…

DDay35 - Tips for refactoring

05/27/20191 Min Read — In Refactoring

Today I had a refactoring session with my mentor Wolfram ≲Refactorer≳ Kriesing 😎 What is refactoring? Uncle Bob defines refactoring as … simple operations that change the structure of code without…

DDay33 & Day34 - TDD Patterns

05/25/20192 Min Read — In TDD

The last two days I mainly spent reading Kent Beck's book TDD by Example. This post summarizes the most important TDD patterns he presents in there. Test-Driven Development Patterns Isolated Tests…

DDay31 & Day32 - Writing my own xUnit Framework

05/22/20191 Min Read — In TDD, Scala

The last two days I started to read Kent Beck's book Test-Driven Development by Example which was recommended to me via Twitter. Compared to his video series, I have to say that I like the book much…

DDay30 - Planning the Business Phase

05/21/20191 Min Read — In BusinessPhase

Today I have started to plan my business phase which will start on 1 June. The business phase, as the second phase of the apprenticeship, enables the apprentice to learn about different teams, their…

DDay29 - Morning Kata: 'Configure your own wardrobe'

05/17/20191 Min Read — In TDD

In the last three morning-kata sessions, Masha and I solved a real-world task which is as follows: Imagine you have just moved into your new apartment, and then you notice that you still need a new…

DDay28 - Some thoughts on Kent Beck's TDD-Session

05/16/20191 Min Read — In TDD

Yesterday and today I watched Kent Beck's video session Test Driven Development. I have to say that I was a bit confused by the way Beck demonstrates TDD in this screencast because I expected it to be…

DDay27 - The Origins of TDD

05/15/20191 Min Read — In TDD

This post provides a short overview of where TDD comes from and how it has evolved. Kent Beck is known as the developer or at least rediscoverer of TDD as stated on Wikipedia. Kent Beck writes on…

DDay20 - On "Integrated Tests Are A Scam"

05/03/20192 Min Read — In Testing

I chose J.B. Rainsberger's talk Integrated Tests Are A Scam as my main topic for the last two days. In his talk, JBrains explains the concepts of Integrated Tests, Isolated Tests and explains why…

DDay18 & Day19 - Apprenticeship - one month in

05/02/20192 Min Read — In Retrospective

It's the beginning of May which also means that my first month as an apprentice came to an end. It's crazy how time flies, really, and this post explains how I reviewed my first weeks. Self-Assessment…

DDay15 - Elixir Processes Part2

04/25/20191 Min Read — In Softwaredesign, Elixir

In yesterday's post I presented a simple Elixir implementation for a Stack process. Today I had a talk with one of my mentors where I got asked how I know which type of messages a process supports or…

DDay14 - Elixir Processes

04/24/20191 Min Read — In Softwaredesign

Today's topic of Dave's video course was 'Elixir Processes'. This post will summarize the really most important information on this. What an Elixir Process is - and what it is not! An Elixir process…

DDay13 - Implicit Knowledge

04/23/20192 Min Read — In Softwaredesign

In today's post I want to pay attention to a topic I stumbled across last week. As you probably know, I have extended Ugurcan's trello-board visualization app for Gitub-Projects support. In order to…

DDay12 - Pattern Matching

04/16/20192 Min Read — In Elixir, Softwaredesign

In today's blog post I'll tell you what I've learned so far about Elixir's pattern matching concepts and which parts are really amazing in my opinion. But first let me tell you a little secret: Elixir…

DDay11 - Focusing

04/15/20191 Min Read — In self-organization

Do you remember my post from Day4&Day5, when I was looking for new ways to organize myself better? Today I'll report which approaches I tried to keep focus on a task and how it worked so far.…

DDay10 - |> The pipe operator

04/12/20191 Min Read — In Elixir

So far I have mainly developed software using OOP languages like Java, Python or Scala. All these languages share some common OOP concepts such as classes for defining custom types, methods for…

DDay9 - What Elixir is about

04/11/20192 Min Read — In Elixir

Today I started my journey with Elixir! Therefore, I decided to go with Dave Thomas's video course 'Elixir for Programmers' for several reasons: This course assumes that you already have programming…

AAbout Clones & Forks

04/10/20191 Min Read — In git, github

Today I came across a situation with Git/Github that I had never encountered before. What happend? Two days ago I cloned Uğurcan's repository Trello Data Visualization to develop an integration for…

DDay8 - How I discovered Elixir

04/10/20191 Min Read — In Elixir, programming

A challenge that every apprentice faces is to learn a new programming language. Most of the former apprentices decided for Scala or Haskell. I already know Scala (at least the basic concepts) since it…

DDay7

04/07/20191 Min Read — In self-organization, React.js, JavaScript

In today's daily meeting the question arose whether an absolute number of completed tasks is suitable to represent the time invested in a certain topic. Theoretically yes, but only in case all tasks…

DDay6

04/06/20191 Min Read — In self-organization, React.js, JavaScript

As already announced in the last blog post, today I mainly took care finding a way to visualize my progress for the indiviual learning categories. Uğurcan, one of the first Apprentices of HolidayCheck…

DDay4 & Day5

04/05/20191 Min Read — In self-organization

It's April 5th today and the first week of the apprenticeship comes to an end. How time flies! I cannot remember any other week in the last months where time has flown by so much! Maybe this was the…

DDay3

04/04/20191 Min Read — In TDD

Yesterday I wasn't able to write a post anymore since my head was just too full of information and thoughts. The reason for this was the TDD (Test Driven Development) session I had with Wolfram in the…

DDay1 & Day2

04/02/20192 Min Read — In Start

It's April 2nd and my second day as an apprentice is slowly coming to an end. The last two days have been full of information and so I’ll try to summarize my impressions in this blog post as good as I…