Notes from a senior engineer on building with AI agents, spec-driven development, and taking AI-built apps to production. Originally published at juliantellez.com.
My phone lit up at 3:22 in the morning with a subject line no cloud engineer wants to read half asleep: AWS Cost Management: Cost anomaly(ies) summary for account [2026-07-17] The body claimed a sin
I asked Claude Code to refactor a module and then I sat there. Not for long. Long enough to open a browser tab, read half a thread about something I did not care about, and lose the thing I had been h
This was an afternoon experiment, so read it in that spirit. The goal was to start real coding work by talking to a speaker: not "set a timer", but "work on the board script", and have an agent plan i
Last month I watched Claude Code write a beautiful authentication module. Clean abstractions, sensible error handling, well named functions. It looked like something a developer would write. Then I ra
I grepped my own name in a codebase I own. Fourteen hits, across nine files. Not in the git log, not in the changelog. In the comments. // One command. Julian: "I dont understand why I need quay panel
Why an agent needs a harness ended with a few things I want from any harness: Real isolation. A visible difference between done and gave up. Permissions built for nobody watching. A transcript that s
A model that can write anything still cannot open a file, run a command, or know when to stop pretending it did. This is the first post in a series on what actually turns a language model into somethi
At the AI Engineer World's Fair in 2025, Sean Grove from OpenAI described how most of us work with coding agents: "We keep the generated code, and we delete the prompt." He compared it to shredding th