About

Hey there! I'm John Berryman, and this blog is where I dump my brain onto the internet.

I'm the founder of Arcturus Labs, where I help startups and enterprises build AI applications that actually work—RAG systems, AI agents, and the kind of LLM applications that don't just sound impressive in pitch decks but survive contact with production. Before hanging out my own shingle, I was an early engineer on GitHub Copilot, helping build the completions and chat features that turned "AI pair programming" from science fiction into your daily workflow.

Before my AI era, I spent years as a search engineer. I helped build the next-gen search system for the US Patent Office (yes, searching millions of patents is exactly as hard as it sounds), developed search and recommendation features for Eventbrite, and worked on GitHub's code search infrastructure. Search is a rabbit hole—once you fall in, you never quite climb out. I even co-wrote Relevant Search with my pal Doug Turnbull to drag other people down with me.

More recently, I co-authored Prompt Engineering for LLMs with Sathvik Nair, Ben Auffarth, and Max Humber, because apparently I hadn't written enough about technologies that change every three months.

This blog is my personal playground for exploring ideas that don't quite fit anywhere else. You'll find posts about algorithms and data structures (I once built a skip list from scratch because I was bored), neuroscience tangents (your brain is doing binaural interferometry and you didn't even know it), philosophy deep-dives (what does it mean to exist? Spoiler: I still don't know), business musings, and whatever random technical curiosities catch my attention. Sometimes I write about my kids' camping trips or the Doppler effect of train whistles. Sometimes I reinvent graph clustering algorithms just to see if I can.

The common thread? I like taking complicated things and figuring out how they work, then explaining them in a way that doesn't require a PhD to understand. I'm fascinated by the intersection of math, code, human cognition, and how all these pieces fit together into systems that are somehow both impossibly complex and elegantly simple.

If you want to chat about AI, search, algorithms, or why consciousness might be the hardest problem in the universe, feel free to reach out. I'm always up for a good technical rabbit hole or a philosophical tangent.

Thanks for reading!