David Lönnhager
Software Developer at Mullvad VPN
Gothenburg, Västra Götaland County, Sweden
Summary
🤩
RockstarDavid Lönnhager is a software developer with 13 years of experience, currently focused on systems and networking at Mullvad VPN in Gothenburg. He brings hands-on expertise in low-level Windows networking, tunnel configuration and route management, combined with a strong track record of fixing deep system bugs and improving performance. His open-source contributions span well-known projects like Pygame, Anki and LibGDX, showing fluency across C, Python, Java and platform-specific JNI/C work. David routinely balances backend systems work with full-stack and mobile concerns, from audio/video rendering deadlock fixes to web UI input issues. Colleagues rely on him for meticulous cleanup, memory-leak fixes and pragmatic API improvements that make complex native features more robust and maintainable.
13 years of coding experience
Github Skills (44)
debug10
javascript10
system-programming10
game-engine10
python10
libgdx10
wp-api10
sdl10
system-design10
c1110
winapi10
networking10
java10
c1710
system10
Programming languages (13)
Github contributions (5)
mullvad/mullvadvpn-app
Oct 2019 - Jan 2023
The Mullvad VPN client app for desktop and mobile
Role in this project:
Back-end & Systems Engineer
Back-end & Systems EngineerContributions:2074 reviews, 2313 commits, 1671 PRs in 3 years 4 months
Contributions summary:David primarily contributed to the core functionality of the Mullvad VPN client app, with a focus on the Windows platform. Their work involved implementing and integrating low-level networking features, especially around route management and tunnel configuration, along with maintaining and fixing issues. The commits demonstrate experience in system programming and Windows-specific networking, with significant changes to the core and low level networking parts.
vpn-clientclient-appelectronrustmullvad
pygame/pygame
Feb 2019 - Dec 2019
🐍🎮 pygame (the library) is a Free and Open Source python programming language library for making multimedia applications like games built on top of the excellent SDL library. C, Python, Native, OpenGL.
Role in this project:Back-end Developer & Library Maintainer
Back-end Developer & Library MaintainerContributions:134 commits, 221 PRs, 311 pushes in 10 months
Contributions summary:David primarily focused on addressing bugs and improving the efficiency of the Pygame library, particularly concerning issues related to file object access and potential deadlocks in the audio and video components. They implemented and refined features in the rendering system, including fixes related to alpha blending and color key handling. The contributions also involve cleanup tasks, such as removing unnecessary code and fixing memory leaks, demonstrating a focus on code quality and performance.
pythongamemultimediaon-topprogramming-language
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