Johannes Ewald
Founder at peerigon
Augsburg, Bavaria, Germany
Summary
🤩
RockstarJohannes Ewald is a founder and seasoned full‑stack engineer based in Augsburg, Germany, with 14 years of experience building developer tools and improving web tooling. As co‑founder of peerigon and a member of the webpack team, he contributes to high‑impact open source projects that power modern JavaScript bundling and CSS preprocessing. His work spans backend test utilities (rewire), CLI tooling (updtr), and loader ecosystems (sass-loader, less-loader, loader-utils), demonstrating a knack for making developer workflows more robust and user-friendly. Johannes often focuses on testability, options consistency, and developer UX—refactoring internals, adding source maps, and improving CI reporting—skills that quietly elevate large ecosystems.
14 years of coding experience
Stackoverflow
17,745reputation
2.3mreached
60answers
6questions
coffeescript
top-5%
npm
top-5%
dependency-injection
top-5%
webpack
top-1%
javascript
top-1%
requirejs
top-5%
Github Skills (46)
asynchronous10
unit-testing10
debug10
javascript10
npm10
jquery10
async10
testing10
css10
configuration-management10
sass10
sourcemaps10
sc10
libsass10
webpack10
Programming languages (15)
Github contributions (5)
webpack-contrib/sass-loader
Mar 2014 - Aug 2018
Compiles Sass to CSS
Role in this project:
Front-end Developer
Front-end DeveloperContributions:28 releases, 291 commits, 142 PRs in 4 years 5 months
Contributions summary:Johannes's contributions primarily focused on modifying the test suite for the Sass loader. They refactored the tests, added source map support, and fixed typos. They also made changes to how the loader handled imports, ensuring correct behavior with both regular and special-cased CSS imports and module resolution. These changes indicate a focus on improving the loader's functionality and ensuring its reliability through comprehensive testing.
sasswebpack-loaderdart-sasscssnode-sass
jhnns/rewire
Jun 2012 - Dec 2021
Easy monkey-patching for node.js unit tests
Role in this project:Back-end Developer
Back-end DeveloperContributions:19 releases, 272 commits, 39 PRs in 9 years 8 months
Contributions summary:Johannes primarily focused on developing a monkey-patching library for Node.js unit tests. The commits demonstrate the implementation of the `rewire` (formerly `trick`) function, which allows for mocking and modifying module dependencies. Key contributions include the ability to inject mocks, modify object properties, and leak private variables within modules. The user also refactored code and added support for CoffeeScript and shebang modules.
patchingnode-jstestingjavascriptmonkey
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