Learn by building real systems.
Free learning paths, build logs, and field notes on software, security, and practical AI, documented from real builds. Receipts included.
Free. No paywall, no course upsell. Written in public by one builder.
Pick a door
Three ways in
Different starting points, same idea: understand the layers by building through them.
The learning path
Start with the abstraction layers: how hardware, browsers, frontends, networks, backends, and business systems actually fit together.
Articles and notes
Field notes and writeups from real builds: what worked, what broke, and how to verify it yourself.
The builds
Working systems and demos behind the notes. The receipts live here: real projects, real configuration, real tradeoffs.
How this works
Build. Break. Document. Teach.
Everything taught here was built or broken first. If a note makes a claim, there is a way to check it.
01
Build
Every topic starts as a real system, not a toy example.
02
Break
The failures stay in. The messy middle is where the learning is.
03
Document
Notes with receipts: configs, repos, and demos you can inspect.
04
Teach
The write-up explains the layers so the next build is easier.
Latest
Recent notes
New writeups land here first.
Fresh notes are on the way. The site just refocused on learning, and the first new writeups are in the pipeline. The learning path is already live.
Built and written by David Ortiz
I build real systems, break things on purpose, and write down how it actually works. This site is where I learn in public.