Mateusz Guzik
Kernel Developer at FreeBSD
Brno, South Moravia, Czechia
Summary
🤩
RockstarMateusz Guzik is a seasoned kernel developer with 14 years of experience specializing in multicore performance, scalability and low-level bug hunting across FreeBSD and Linux. Currently at Netgate and a long-standing FreeBSD committer, he has a track record of shipping high-impact fixes and performance optimizations in flagship projects such as the Linux kernel and OpenZFS (notably contributing FreeBSD port improvements and lock/caching optimizations). His background includes production debugging and backporting at Red Hat, kernel scalability work funded by The FreeBSD Foundation, and co-authoring a NAND-focused log-structured filesystem early in his career. Based in Brno, he blends pragmatic systems engineering with deep kernel internals, routinely addressing subtle issues like tqid overflows, symlink caching, and branch prediction to squeeze real-world performance. Colleagues know him as a friendly, meticulous engineer who prefers solving hard kernel problems over chasing buzzwords.
13 years of coding experience
13 years of employment as a software developer
English, Polish
Github Skills (11)
c1710
memory-management10
system10
filesystem10
openzfs10
c1110
system-programming10
linux-kernel10
freebsd10
performance-optimization9
git5
Programming languages (10)
Github contributions (5)
openzfs/zfs
Sep 2020 - Jan 2023
OpenZFS on Linux and FreeBSD
Role in this project:
Backend Developer
Backend DeveloperContributions:39 reviews, 80 commits, 44 PRs in 2 years 4 months
Contributions summary:Mateusz primarily contributed to the FreeBSD port of OpenZFS. Their work focused on optimizing performance by converting locks, updating cache usages, and fixing issues related to tqid overflow, as well as adding missing fplookup handlers. Furthermore, they addressed several version bumps and introduced branch predictions. They also addressed build failures due to locking issues.
openzfstarballlinuxfreebsdsystem-software
torvalds/linux
Jan 2023 - Jan 2023
Linux kernel source tree
Role in this project:Back-end Developer
Back-end DeveloperContributions:2 commits in 1 day
Contributions summary:Mateusz primarily contributed to the Linux kernel, focusing on optimizing and refactoring various aspects of the code. Their work involved improving file system performance by caching symlink lengths and improving code efficiency. The user also addressed several bugs and made enhancements related to core kernel functionality, including pid management, memory management, and file system operations.
kernellinux-kernellinuxkernel-source
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