Denys Fedoryshchenko

# about

I’ve spent the better part of two decades close to the metal: running an ISP in Lebanon, chasing kernel panics on production routers, and reporting — then helping fix — regressions on the Linux netdev and LKML lists. These days I work at Collabora on KernelCI, the community effort to test the Linux kernel continuously across a fleet of real hardware.

I sit on the KernelCI Technical Steering Committee and help lead the Dashboard working group. The thread running through all of it: infrastructure should be observable, reproducible, and cheap enough that anyone can run it. When the budget is two dollars and a microcontroller, even better.

# what I work on

Kernel testing & CI

KernelCI — continuous integration for the Linux kernel on real boards, plus the dashboard that makes the results legible.

Networking

Maintainer of Accel-PPP, a high-performance PPP/PPPoE/L2TP/PPTP/IPoE server used by ISPs to terminate subscriber sessions at scale. A fair number of netdev bug reports carry my name too.

Embedded & hardware

ESP32 boards with native Ethernet, inexpensive programmers, and hardware security keys that cost about the price of a coffee.

Consulting

Independent consulting in Lebanon — turn-key network infrastructure for ISPs, from subscriber management and BNG to monitoring and the racks it all runs on.

# selected projects

• cedarkey

  Hardware SSH key storage for about two dollars. Keep your private keys off the laptop and on a tiny dedicated device.

  C ★ 155

• ESP32ETH

  ESP32 with native wired Ethernet over the LAN8720 PHY, Arduino-compatible. For when Wi-Fi just won’t do.

  C++ ★ 30

• Accel-PPP

  High-performance PPP/PPPoE/L2TP/PPTP/IPoE access concentrator for Linux, terminating subscriber sessions at ISP scale. I maintain it.

  C networking

• ESPFLASHER

  An inexpensive programmer for ESP32 / ESP8266 modules — cheap to build, easy to reproduce.

  hardware

• collmon

  A monitoring kit wiring together VictoriaMetrics, Grafana, and collectd into something you can stand up in an afternoon.

  Shell observability

• sysadmin-tools

  A grab-bag of small utilities accumulated over years of keeping systems alive.

  C

→ 180-plus repositories on GitHub.

# elsewhere

• GitHub github.com/nuclearcat
• Email nuclearcat@nuclearcat.com
• Twitter @nuclearleb
• Telegram @nuclearcatlb

CV available on request — just drop me a line.