After last year’s pandemic shock, this year has brought more hope and motivation to people. I’ve felt motivated to learn new things, deep-dive into unknown areas and finally change some things in my life. In this post I’ll share with you my most valued (software) tools, productivity tips, some books worth reading and finally some failure and success with regards to my habits.


Wim Hof Method

Last year just before the (pandemic) winter blues was about to begin I’ve had enough of that feeling something you cannot control was already part of my daily life. Seeking for more self-control and that “I’m still alive” feeling, I’ve decided to go for The Wim Hof Method.

I was determined to cold shower every day and do breath work as well. Breathing exercises were not new to me since I was practising Pranayama for a while.

After some weeks of practice cold was not an enemy anymore. My body (and also my mind) adapted to that kind of stress and soon I was able to go out without any jacket, just wearing a t-shirt - and my trouses of course :) Eventually I was able to keep my habbits and around February I was “bathing” in snow in my swim shorts. Besides that, during my breath work sessions I managed to hold my breath for more 3 minutes - several times. All this success motivated me to keep going and make my new habbits part of my life style.


As you know you can always browse my digital bookshelf in my personal Zettelkasten. This year I’ve read more IT related books than last year. I’ve especially focussed on Software Architecture, Golang and DevSecOps.

Clean Architecture architecture

If you write code and don’t know Uncle Bob then you’ll have to read this book. Since my background is not of software engineering I had to learn a lot about good coding principles and how to structure my code properly. Very early in this process I came across Uncle Bob’s famous Clean Architecture diagram which describes how to structure your software project into different layers.

Well then I was blindly using those principles in my software projects without knowing that Clean Architecture is more than a diagram and some depedencies between some layers. I’m glad I’ve finally managed to read this book (along with The Clean Code and The Clean Coder which were not that good as this one) and learn more about engineering principles and software architecture in general. Additionally I think SOLID principles should be part of every (software) engineer’s skills repertoire.

You think good architecture is expensive, try bad architecture. – The Clean Architecture - Note 2

I was also surprised that Hexagonal Architecture (also known as ports and adapters architecture) almost has the same principles. I also recommend DDD, Hexagonal, Onion, Clean, CQRS … How I put it all together reading. An excellent article!

Black Hat Go golang

Back at Scout24 we were mainly using Python for our internal services and tools. But I wanted to make my colleagues more aware of Golang’s capabilities and introduce this language to the team. Instead of some standardized approach (core types, basic control flows, “classes”, interfaces etc.) I wanted to actually do something with the language that might catch people’s interest.

Black Hat Go was the right book to start with. It gives you just enough details to get you started with the language and then you start implementing network scanners, keyboard loggers, DNS tunneling tools (like chashell) and much more. I used some of the examples in the book to introduce my team to offensive hacking while showing Golang’s key features (go routines, interfaces, composition instead of inheritance etc.) Also if you’re a pentester and need to cross-compile your tools for different architectures, this book is definitely for you.


About the science of Lean software and DevOps. I wrote an extensive summary in my last blog post.

Agile Application Security appsec

I consider this book to be the best one I’ve read on Application Security in the last years. And I’ll tell you why: When was the last time that a cool defensive mechanism/measure/technology (beside the cyber-security branded vendor X products) had a cool name like Logjam, Shellshock or Heartbleed? I know vulnerability research, exploit development and some cool hacks are fun. But this is not what’s needed to build a Security minded culture inside some organization. This is also not what developers (and everybody else included in the software engineering process) need to know. In an Agile world different roles have to work together: Developers need to understand and adopt Security best practices and also take responsability for the security of their systems. You build it, you run it and you also keep it safe and secure!

Product owners/managers need to understand security/compliance requirements and give agile teams enough time for the implementation of the security measures. And last but not least: Security professionals will also have to adapt to the Agile world. They need to learn to accept changes more often, to work faster and manage Security risks in incremental terms. And most important: Security needs to become an enabler and not a blocker!

Go with the Domain ddd

If you know about Three Dots Labs already and also have read their blog series on Domain-driven Design with Go then you don’t necessarily need to read this book. I think the content is quite good and has to be “diggested” over a longer period of time. However, if you’re not familiar with Domain-Driven Design principles this book might be to much for you. Also be prepared to invest a lot of time in their Go DDD example application and carefully read the code. After reading their blog posts first I was expecting to mind more context/background information in their book. This was not the case and I also don’t blame them for this. Writing a book (and also blog posts) is very time intensive especially when you don’t have that much time available.


I remember when I first started reading the first 20 pages and I was shocked how much of our today’s world was part of the environment described. Also this book got recommended to me several ways but it was until the pandemic that I had enough motivation to push myself through. I’m not a Sci-Fi fan and usually you won’t find this kind of book genre in my bookshelf. But I’ll add this one to the “must reads”. Eventually I’ll read it again in some couple of years just to find out what happened since last time I did so. I guess there is a reason this book belongs to the best selling ones and I definitelly recommend it to everyone interested in politics, history and of course Sci-Fi.

Das Experiment sind wir

In English: “We are the experiment”. Despite its rather controversial title, I read this book at the beginning of the year after listening to this podcast: Das Interview: Fluch und Segen exponentiellen Wachstums (in English: Curse and blessing of exponential growth). This book got me into the basics of CRISPR/Cas9 and mRNA. It also made me think about schooling and education systems which (at least in Germany) don’t really teach students about complex systems/mechanisms that surround us. And to be more specific: AI/ML basics are not taught at school, benefits of CRISPR gene editing are often ignored by mass-media. Instead people have this feeling they’re part of something that happens to them instead of being part of that something. You could apply this to Corona and many other global challenges (climate change?) that will follow in the next years.


I remember someone said to me I should read this book because Bill Gates recommended it. And it turned out this book changed the way how I see the world. But most important: It showed me that my knowledge about the world is kind of out-dated. Just to give you an example: Before reading the book I thought the world was divided into 3 parts/classes. We tend to classify countries around the globe in developed economies, economies in transition and developing economies. But if you look at the data - at this book is definitelly data-driven - you’ll notice that you can divide the world on a 4 category model based on income per person (check Four income levels at Wikipedia). And this is just one example. If you want to self-test your views/knowledge make sure you do this at (they also have really awesome visualizations).

The Plant Paradox

Initially I wasn’t sure if I should write a summary on this one. And that’s because this one is the type of books you know it contains somehow false affirmations but the are some that make you ponder. Since 2 years I constantly try to adjust my Nutrition based on information I get from different books. After reading How not to die last year I think I managed to get most of my nutritional biases under control. I also managed to get a deeper understanding of the bio-mechanics that make our bodies so interesting. Well The Plant Paradox tries to turn scientific based nutritional knowledge upside down. At the core of the “paradox” are lectins that are mostly found in all foods, especially legumes, fruits and grains. The author claims that these tiny proteins cause gut permeability and therefore inflamations that drive auto-immune diseases. While Dr. Gundry’s thesis seems to be wrong (and yes, I’m fan of Dr. Greger) and most of the lectins can be removed by (pressurized) cooking, I still think there are some small grains of truth in there. I also recommend reading this summary (in German) which provides more cross-doamin knowledge related to different aspects of the thesis.


Almost one year ago - and definitely after reading Atomic Habits - I was looking for a digital habit tracking tool. My motivation was not to develop new habits but stick to existing ones and have a visual dashboard how well I’m doing. After giving up my Bullet Journal tracking page, I’ve finally found Loop Habit Tracker which accompanies me every day.

I use widgets on my (Android) where I can easily toggle multiple habits as done with simple clicks. The advantage of using widgets is the fact you don’t have to first run the application and then toggle the habits. Usually after my morning routines, I just go through my habits and click accordingly.

In the following sections you’ll see different heat maps related to some habit. They show you on which days a specific habit activity took place or not.


I use 7mind for my morning meditation. Usually I don’t track my meditation time but from times to times I do longer session (up to 20 minutes). As you can see I usually don’t meditate at the weekend since I rather spend time with my family and prefer not to wake up that early.

Cold shower

After reading more about The Wim Hof Method I was determined enough to take cold showers on a regular basis. I’m pretty happy I managed to stick to this habit throughout the year.

Breath work

This is the type of morning exercise that boosts up my energy level after waking up. I usually do alternative nostril breathing (Yoga), break work after Wim Hof (I would say 80-90% of the time I do 3 rounds of 50 inhale/exhale rounds) and most recently also SOMA breath.


I’m not happy with this one since I know I could have read more. It’s just that I use to have multiple projects running in parallel so I need to apply some time-slicing to my available time. What also keeps me busy from reading more is the fact that always do some post-reading after each book: I collect notes/thoughts, I re-read interesting pages/concepts, put everything into my Zettelkasten. I’m already looking for a better reading workflow. Maybe you have some ideas.


Yes, this is the most embarrassing one. I was somehow motivate to do more sports beginning with April but after June that kind of faded out. Next year I definitely want to do more workout, at least once a week. I also want to combine my bodyweight training (calisthenics) with climbing.



I started going down the “Emacs rabbit hole” almost 2 years ago. And I still don’t regret doing so, although I’ve spent hours of debugging, trial and error, random copy&paste of Elisp code. Also switching from Spacemacs to Doom Emacs had a huge boost regarding my productivity in Emacs. Now I can say I do understand most of my configuration (see my dotfiles) whereas one year ago I was randomly copy&paste and putting pieces together in the hope they’ll somehow work.


My top modules for this year:

Configuration management

I use to keep my configuration files in a dotfiles repository, publicly available. This year I had to keep custom configurations for 4-5 machines in different contextes (work, private). So I needed to find a way how to manage configuration files and apply customizations depending on the machine where that specific config was needed.

Initially I came across dotbot which is written in Python and uses a YAML/JSON configuration file in order to setup your dotfiles. But then I’ve found chezmoi.


This little Golang utility will manage your dotfiles across multiple machines in a secure manner. Among the top features:


Password management is not easy, especially when you want to stay away from commercial solutions. I wish I knew pass before I bought LastPass premium. Here are the reasons why I like this little tool:



If you have troubles keeping yourself focussed and tend to do multi-tasking, then I recommend you should use a pomodorro timer. At least since my son got born, I don’t have that much time available as I used to have some years ago. Becoming a parent indeed changed the way I define productivity. I can not concentrate on one task during a large period of time because I always get “distracted”. I need to do some grocery shopping, I need to pick up my son from the kindergarten, I need to to some household… you name it. So I had to find a way how to work on several projects/tasks (in a private but also work context) but in small chunks of work.

After using this technique for years now, I’m pretty sure it is one of my personal most efficient productivity tools. Just use a (clock) timer, an application on your smartphone or to get you started. Do rounds of 25-30 minutes (one pomodorro) and do a larger break after 4 rounds. Believe me, you’ll notice the difference.


By now you should know I’m obsessed with time tracking and being productive in multiple contextes. But sometimes I forget to start my pomodorro timer and at the end of the day I don’t know how much time I’ve spent working on a specific task. You can all this with Emacs and org-pomodoro but for those of you non-Emacsers there is They have plugins for almost everything: Shells, IDEs, Excel, Powerpoint etc.

If you have data privacy concerns, you might want to hidden project and file names (also check out my wakatime configuration file).

Loop Habit Tracker

Sticking to healthy habits is important. Tracking your progress will remind you to act. You have your progress in front of you and that will eventually motivate you. You don’t feel motivated enough? Then you might apply the paper clips strategy. Whatever you do: Track your progress and be honest to yourself. Don’t push yourself to hard, just treat yourself well and stick to your habit.


For the upcoming year I’d like to

That’s it for now. Please share your favourite tools/productivity tipps as well as random comments/thoughts.