Building with AI
Welcome to Koffey
Koffey is now an ideas hub: building apps with AI, staying strong after 40, and explaining infrastructure in plain English — all built in public.
Built in public
Ideas, builtand tested.
Koffey is where Johnny builds apps with AI, stays strong after 40, and explains the infrastructure behind it all — in plain English.
The Pillars
Three threads, one notebook
Building with AI
Apps built in the open, with AI doing the heavy lifting.
LatestWelcome to Koffey
All postsFitness Over 40
Strength and energy that hold up past 40.
First notes coming soon.
All postsInfrastructure, Explained
The machinery behind the internet, in plain English.
First notes coming soon.
All postsLatest writing
All notes →In the Workshop
What we're building
The apps behind the posts. Everything ships in the open.
Open source
Koffey CRM
An AI-native CRM built around natural conversation instead of forms. Talk to it like a colleague — it captures, organizes, and retrieves your sales data.
About the productFree tool
GPU Capacity Planner
Estimate how many GPUs your AI workload actually needs — and what it will cost — without needing an infrastructure background.
Try the plannerFAQ
Common questions
Follow along
New notes on building, lifting, and the machinery behind the internet — as they happen.