Joe Karlsson - Software Engineer & Developer Advocate

cat about.md

## about.md

Joe Karlsson

he/they · software engineer · dev advocate

Hey, I'm Joe. I help developers build cool stuff - through demos, blog posts, talks, videos, whatever works.

Leading DevRel at CloudQuery. Outside of work I run a 40+ container homelab, watch way too many movies, and build things that probably shouldn't be connected to the internet.

I once built an IoT cat toilet and gave a conference talk about it. Also a TEDx speaker. I contain multitudes.

blog/ about/ work/ uses/ contact/

cat now.md

working on

Leading DevRel at CloudQuery

tinkering with

A 40+ container homelab running Proxmox, Home Assistant, and way too many arr apps

writing about

Self-hosting, databases, and things that probably shouldn't be connected to the internet

using

M3 Pro MacBook Pro, VS Code, too many monitors. See my full setup →

ls projects/ --sort=stars

See all →
Data Structures

Data Structures & Algorithms in JS

185
JavaScript Algorithms
React Spotify Player

React Spotify Player

131
React Spotify API
Bechdel.io

Bechdel.io

30
Node.js NLP
IoT Kitty Litter Box

IoT Kitty Litter Box

25
Raspberry Pi Node.js

ls posts/ --featured

Hero image for How to get started building a Homelab server in 2026
Sep 26, 2023

How to get started building a Homelab server in 2026

I built my first Homelab server for under $200 using a used Lenovo ThinkServer from Facebook Marketplace and Proxmox. Here is everything I learned about picking hardware, choosing an OS, setting up containers, and mounting NAS storage.

 Hero image for An Introduction to IoT (Internet of Toilets)
Nov 2, 2020

An Introduction to IoT (Internet of Toilets)

My favorite things in life are cats, computers, and crappy ideas, so I decided to combine all three and explore what was possible with JavaScript by creating a brand-new Internet of Things (Internet...

 Hero image for How to get started with Home Assistant in 2023
Feb 27, 2023

How to get started with Home Assistant in 2023

Are you looking to turn your home into a smart home? With the help of Home Assistant, you can easily automate tasks and make your home more efficient. In this blog post, I’ll share my experience of...

ls posts/ --recent

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Hero image for Implementing MikroTik's Binary API Protocol in Python from Scratch
Mar 4, 2026

Implementing MikroTik's Binary API Protocol in Python from Scratch

A deep dive into implementing MikroTik's proprietary RouterOS binary API protocol in Python — variable-length encoding, sentence-based messaging, and programmatic network infrastructure control. Zero dependencies, 137 lines.
Hero image for My Homelab Two Years Later: From Desktop Tower to Server Rack
Mar 4, 2026

My Homelab Two Years Later: From Desktop Tower to Server Rack

How my homelab grew from a $200 ThinkServer to a dual R730 server rack with 60+ containers, 10G networking, GPU-accelerated AI, and real power monitoring data from Home Assistant.
Hero image for Building a Real-Time Digital Graffiti Wall with MongoDB Realm and RGB LEDs
Feb 4, 2026

Building a Real-Time Digital Graffiti Wall with MongoDB Realm and RGB LEDs

How I built an interactive art installation and collaborative drawing app where multiple users draw on a shared digital canvas that displays their creations live on a physical RGB LED grid, using MongoDB Realm for real-time sync.
Hero image for Building a GPU-Accelerated Subtitle Generator for My Video Library
Feb 4, 2026

Building a GPU-Accelerated Subtitle Generator for My Video Library

How I built a self-hosted subtitle generation pipeline using GPU-accelerated Whisper AI on my homelab — with parallel workers, VRAM-aware scheduling, automatic language detection, and a multi-layer hallucination filter. A practical faster-whisper guide for video libraries at scale.
Hero image for Building a Claude Code Blog Skill: What I Learned Systematizing Content Creation
Oct 23, 2025

Building a Claude Code Blog Skill: What I Learned Systematizing Content Creation

I live in the terminal. Like, really live there. As a developer advocate, it’s where I spend most of my time - running commands, testing code, writing docs. Over the past few months, Claude Code...
Hero image for I Replaced Alexa with a Dumber Voice Assistant (But at Least It’s Private)
Jun 17, 2025

I Replaced Alexa with a Dumber Voice Assistant (But at Least It’s Private)

After five years of building automations in Home Assistant, I finally pulled the trigger on something I’d been contemplating for months: completely replacing my Amazon Alexa ecosystem with Home...
DATABASES • SMART HOMES • IoT • DEVREL • OPEN SOURCE • HOMELABS • FILM • CATS • WEIRD PROJECTS • CONFERENCE TALKS •