Why this site exists

I am Yoonsoo Park, a software engineer who learns by building, operating, and writing down what survives contact with real systems.

This site is public evidence of that growth. I turn experiments, production lessons, corrected assumptions, and architectural decisions into material another engineer can use at work. When an older approach stops being sound, I keep its history visible and point to the maintained replacement.

What you will find

• AWS and agent systems with explicit security, cost, and operational boundaries.
• Software architecture and platform decisions with their tradeoffs intact.
• Salesforce, Python, TypeScript, DevOps, and self-hosting field notes.
• Article Atlas expeditions that connect several sources into one practical decision.

Start with the safe agent operations expedition, browse every article, or explore Article Atlas.

The name “thats.nono” comes from documenting the pitfalls—the moments where a shortcut looks reasonable but fails under real constraints—so the next person does not need to repeat them.

You can inspect the work on GitHub or contact me.