Hi, I'm Johannes.
I write about React, professional dev skills, and career advice.
I'm also the creator of Profy.dev, where React developers can build a project for their portfolio using professional workflows.
Popular Articles

Don't waste your time on a portfolio website

Oct 20, 2020

First of all, sorry for the clickbaity title. But give me a minute and hear me out. You can see it all the time: new developers spending a lot of time trying to get their portfolio websites right. In the hope to land a great job, they put in hour after hour building custom layouts that are supposed…

An in-depth beginner's guide to testing React applications in 2020

Jun 24, 2020

import Newsletter from 'components/Newsletter' Most developers know it: Automated testing is important. There are many reasons arguing for it. You might unknowingly break an app whenever you change a line of code. Manually testing your app after each change is cumbersome. Tests help document edge…

Frustrating job search? My #1 tip for outstanding portfolio projects

Feb 14, 2020

Applying for jobs can be a frustrating experience. Especially if you don't have professional experience yet. You apply and apply but rarely even get replies. Every job posting requires experience. But how are you supposed to get it if nobody wants to hire you? At the same time, you hear a lot of…

React debugging session - Why is this function called hundreds of times?

Mar 27, 2020

Every developer knows this situation: You're writing your code, hammering your keyboard all day long. Your code seems to work. Until it doesn't. Either it's not working as expected at all or only in some situations. You try to find the problem. You have a close look at the code. But nothing seems…

Inside a dev's mind - How do you plan a UI feature?

Apr 18, 2020

When developing a new feature many of us developers tend to jump into it via programming instead of planning the architecture out first. It may seem easier to start programming. But this often ruins us. We take the wrong approach and don't realize it until we've wasted too much time trying to…

Junior to Senior - Refactoring a React pan and zoom image component

Nov 07, 2019

This post is part of a series about refactoring React components The goal of this article is to help software developers write high-quality code. Even good, experienced engineers often have trouble with code-readability or don't emphasize it. At least this is what I experience almost whenever I jump…