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Data Applications "Data is the new oil", "we need to be data driven", "we need to apply AI to keep being competitive" are some of the prashes I hear a lot. As I haven't seen yet a clear article pointing out what is done with the data ... here you are 🙂 Why it's … Read More »

Bucketing in A/B-Testing Bucketing users in two groups is a key part in A/B testing. We need to randomly assign users to a bucket. And in practice, we need to make sure a user is assigned to the same bucket consistently. First, we need a user identifier. Database Solution We want to … Read More »

Simulated Annealing This article is not quite finished, but I recently wanted to share some ideas. Simulated Annealing is an optimization algorithm. It is well-suited for combinatoric problems. Confusion Matrix Ordering A confusion matrix contains the predictions of a classifier together with their ground truth. The cell \((i, j)\) gives the information … Read More »

Scientific Writing Writing a paper or a thesis in Computer Science is in some ways very different from writing an essay or a blog post. I figured those out by accident and would like to help my readers to be directly aware of them. If you want to get a better introduction … Read More »

Cost of Living How expensive is my style of living? How different would it be in other parts of the world? How does inflation affect me personally? How much would I have to pay if I lost all my stuff at once (e.g. a fire or moving without my stuff)? I wanted … Read More »

How to hold good Presentations Presentations are a common way of knowledge sharing. Most people have to hold a couple during their school time, during their studies at university and at work. I always made a lot and I feel very comfortable holding presentations. After my latest one, I was asked how I create them … Read More »

jq jq is a command line tool for processing JSON data. It is useful when executing small ad-hoc tasks. In this sense, it is similar to sed, awk and grep. It is very good for the first step in exploratory data analysis: Getting an idea what you actually have. Installation # Ubuntu … Read More »

Ansible Ansible is a configuration management tool maintained by Red Hat. It has to be installed on a controll machine. On the target machine, no configuration is needed. The control machine connects to the target machines via SSH. Which problem does it solve? In short: Ansible makes configurations repeatable. Why this … Read More »

Fitness Trackers Fitness trackers are devices which measure things like walked distance and heartbeats. They are usually writstbands. I recently got excited by them and gave them a try. I tried the Mi Band 4. It is one of the cheapest fitness bands which still had very good reviews. I was not … Read More »

Password Managers I recently thought about good solutions for passwords in general. I have found one with which I was ok for a while, but more and more services get compromised. Try haveibeenpwned.com or Firefox Monitor to see if you are affected. One easy way to keep the damage small is … Read More »