Matthias Käppler
Staff Software Engineer, Software Supply Chain Security - Authentication
Berlin, Germany
Summary
👤
Senior🎓
Top SchoolMatthias Käppler is a Staff Software Engineer based in Berlin with 16 years of professional experience and over two decades of programming practice, currently focused on software supply chain security and authentication at GitLab. He has deep hands-on experience building and maintaining large consumer-facing systems and production engineering platforms, and previously drove application performance and reliability work at GitLab and SoundCloud. An active open-source contributor, Matthias has improved core Android tooling and RxJava/RxAndroid concurrency primitives, showing an ability to bridge mobile, backend and tooling domains. He excels at aligning technical and non-technical stakeholders, mentoring colleagues, and turning complex security and performance requirements into pragmatic, testable solutions. A background in computer science and economics underpins his pragmatic engineering approach and interest in systems that scale reliably for millions of users.
16 years of coding experience
13 years of employment as a software developer
Dipl.-Inf. (~MSc) Computer Science Economics, Dipl.-Inf. (~MSc) Computer Science Economics at RPTU Kaiserslautern-Landau
German, English
Github Skills (23)
unit-testing10
rxjavafx10
android-development10
java10
javas10
hmac-sha110
android10
rxjava10
maven10
proguard10
oauth10
concurrency10
api-design9
flow-control9
robolectric9
Programming languages (17)
Github contributions (5)
mttkay/signpost
Nov 2009 - May 2011
A light-weight client-side OAuth library for Java
Role in this project:
Back-end Developer
Back-end DeveloperContributions:89 commits, 1 comment in 1 year 6 months
Contributions summary:Matthias primarily worked on the core logic for the OAuth library. Their contributions focused on implementing signature generation for various OAuth methods, specifically for HMAC-SHA1 and plain text signing. They also introduced the concept of an abstract OAuth provider and further refined the project's architecture, refactoring code for cleaner responsibilities and greater flexibility.
light-weightlightclient-sideoauth2java
ReactiveX/RxAndroid
Aug 2013 - Dec 2014
RxJava bindings for Android
Role in this project:Mobile Developer (Android)
Mobile Developer (Android)Contributions:69 commits, 22 comments in 1 year 3 months
Contributions summary:Matthias primarily contributed to the RxAndroid library, focusing on extending RxJava's capabilities for Android development. Their work involved creating a `HandlerThreadScheduler` for scheduling actions on Android's Handler thread, adding support for Robolectric testing, and refactoring existing code to improve efficiency. Furthermore, the user enhanced the library's integration with Android UI components, implementing an observer class for proper UI thread handling.
kotlinrxjavaandroid
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