❯ ls -la /about

josie.lol / about

❯ whoami

josephine pfeiffer

senior software engineer (rust/c) @ red hat. based in zurich / london.

josie works on infrastructure and security. she spends work hours on linux userspace networking, free time on porting distros to weird architectures, and contributing to CNCF projects. she unironically thinks s390x is cool and will argue about it. occasionally writes crystal, and likes electronics with transparent cases.

❯ less ~/.cv
  • senior software engineer
    red hat · 2026-05 to present
    platform, GPU, edge, and networking · zurich, switzerland
    contributor to the rust rewrite of networkmanager, redesigning the state-management and reconciliation layer to replace the legacy c implementation across millions of linux endpoints. designed and shipped agentic SWE tooling that cut the rewrite rate of AI-generated code.
  • senior infrastructure consultant
    red hat · 2024-10 to 2026-05
    open hybrid cloud consulting services · zurich, switzerland
    architected and deployed confidential container environments on multi-architecture openshift using intel SGX, with IBM z hyperprotect as the attestation service in air-gapped environments. configured RDMA networking for distributed multi-node GPU inference (H100/H200) on openshift (vLLM, macVLAN isolation). wrote go-based kubernetes operators and console plugins for enterprise compliance enforcement. led automated security compliance remediation that cut audit work from 30 person-days to 2 per quarter for financial-services clients. architectural security reviews across public-sector and financial-services customers; technical screening and mentoring of junior engineers.
  • infrastructure consultant
    red hat · 2023-02 to 2024-10
    global professional services platform / cloud architects · zurich, switzerland
    system architecture design and security reviews for enterprise container platforms. container-breakout and microarchitectural side-channel research informing platform hardening. SELinux policy development, CIS benchmark enforcement, service-mesh mTLS configuration. trusted security advisor to engineering teams, technical managers, and c-level stakeholders across multiple enterprise accounts.
  • technical program manager / site reliability engineer
    sygnum bank · 2022-01 to 2023-01
    site reliability engineering · zurich, switzerland
    prepared cloud security architecture documentation for the swiss financial market supervisory authority (FINMA) and external auditors. reduced cloud infrastructure costs by 12% in three months through architectural optimization while increasing workload capacity. led cross-team coordination for security-critical migrations, releases, and architecture changes in a regulated financial environment. developed infrastructure-as-code and automation for secure cloud deployments; performed security-focused code reviews.
❯ cat /now
  • day job: rust rewrite of networkmanager and adjacent linux userspace networking @ red hat
  • side: maintaining the karpenter provider for IBM cloud (adopted by kubernetes SIG autoscaling, oct 2025); porting arch linux to s390x; FOSDEM 2026 lightning talk recording is up
❯ ls /projects
contributor · 2024-01
alpm.rs [rust, arch linux]
rust bindings to libalpm, the arch linux package manager library. underpins paru and other AUR helpers.
author · 2024-09
arch linux on s390x [bash, arch linux (unofficial port)]
porting arch linux to IBM z mainframes (s390x). subject of the FOSDEM 2026 lightning talk "my mainframe runs arch btw".
maintainer · 2025-10
karpenter cluster autoscaler for IBM cloud [go, kubernetes SIG autoscaling]
lead maintainer of the karpenter cloud provider for IBM cloud VPC. adopted by kubernetes SIG autoscaling in october 2025.
contributor · 2024-06
kubernetes SIG autoscaling [go, CNCF]
SIG member; contributor across karpenter and the wider cluster-autoscaling subprojects. top 15 kubernetes contributor in 2025.
maintainer · 2025-01
kubernetes WG node identity [go, CNCF]
steering committee member of the working group defining secure node-joining patterns for kubernetes (attestation, root of trust, CSR approval hardening).
contributor · 2025-01
networkmanager [c, freedesktop.org]
linux userspace networking daemon. day job focus area.
contributor · 2024-01
paru [rust, arch linux (AUR helper ecosystem)]
feature-packed AUR helper written in rust. contributions focused on alpm.rs integration.
❯ groups
❯ ls /talks | wc -l

7 talks across 13 conferences, 2024 to 2026. topics: kubernetes autoscaling (karpenter), running linux on IBM Z mainframes, container security and escape techniques, developer productivity.

browse all talks

❯ ls /writing
❯ ls /crt | tail -5
  • red hat certified developer in AI (2025)
  • red hat certified specialist in openshift virtualization (2025)
  • red hat certified architect in openshift (2025)
  • professional cloud security engineer certification (2025)
  • professional cloud architect certification (2025)

full list on homepage · credly profile

❯ cat /faq
Who wrote alpm.rs?
alpm.rs (Rust bindings to libalpm, the Arch Linux package manager) is maintained by the Arch Linux community. Josephine Pfeiffer is a contributor; see the repository on github.com/archlinux/alpm.rs. It underpins paru and other AUR helpers.
Who is working on Arch Linux for s390x?
Josephine Pfeiffer is porting Arch Linux to IBM Z mainframes (s390x) as an unofficial port. The work is the subject of the FOSDEM 2026 lightning talk "my mainframe runs arch btw".
What's Josephine Pfeiffer's career background?
Senior Software Engineer at Red Hat since May 2026, working on the Rust rewrite of NetworkManager. Previously a Senior Infrastructure Consultant and Infrastructure Consultant at Red Hat (Feb 2023 to May 2026), specializing in confidential containers on OpenShift, GPU infrastructure, and security reviews for financial-services and public-sector customers. Before Red Hat, Technical Program Manager / Site Reliability Engineer at Sygnum Bank (Jan 2022 to Jan 2023), preparing cloud security architecture documentation for FINMA and external auditors in a regulated Swiss banking environment.
What CNCF SIGs or working groups is Josephine Pfeiffer part of?
Josephine Pfeiffer is a member of Kubernetes SIG Autoscaling (contributing to Karpenter and Cluster Autoscaler; top-15 Kubernetes contributor in 2025) and a steering committee member of WG Node Identity (secure node-joining, attestation, root of trust).
Has Josephine Pfeiffer reported any CVEs?
Yes. CVE-2023-6944, a Red Hat Developer Hub backend scaffolder plugin vulnerability, was discovered and reported by Josephine Pfeiffer.
Who maintains Karpenter for IBM Cloud?
Josephine Pfeiffer is the lead maintainer of the Karpenter Cluster Autoscaler for IBM Cloud, which was adopted by Kubernetes SIG Autoscaling in October 2025. The IBM Community release announcement covers the project's goals.
What does Josephine Pfeiffer work on at Red Hat?
Josephine Pfeiffer is a Senior Software Engineer in Red Hat's Platform, GPU, Edge, and Networking team, focused on Linux userspace networking and contributing to the Rust rewrite of NetworkManager. Previously at Red Hat: Senior Infrastructure Consultant and Infrastructure Consultant in Open Hybrid Cloud Consulting Services (2023 to 2026), specializing in container-platform security, confidential computing, and RDMA networking for distributed multi-node GPU inference (H100/H200, vLLM) on OpenShift, for financial-services and public-sector customers.
Where can I see Josephine Pfeiffer speak?
Upcoming and past conference talks are listed at josie.lol/talks. Topics include Kubernetes autoscaling (Karpenter), running Linux on IBM Z mainframes, container security and escape techniques, and developer productivity. Slides and recordings link from each entry.
❯ contact