AI Engineer · Full-Stack Architect · Founder
김영삼 · Youngsam Kim
30 years in development · Running 16 businesses · Author of 3,000 technical glossary entries · 8M cumulative views
"Only those who have crossed the line know there was never a line at all."
From AI agents to full-stack architecture to my own infrastructure — from the rare vantage point of one person who spans the entire stack, I deliver only solutions I have built, run, and proven myself.
How I Work
Working principles forged over 30 years in the field
Security is decided at the design stage
Security is not something you "bolt on" later — it must be decided together with the very first schema, permission model, and network boundaries. Security added afterward almost always leaves holes.
A system you can't observe is a system you can't operate
I treat Logs, Metrics, and Traces as essential design deliverables. A service with no SLI, SLO, or error budget isn't "in operation" — it's "being neglected."
Never trust LLM output — only use it in verifiable ways
Structured output, enforced schemas, guard models, and HITL approval checkpoints are my defaults. I don't try to solve quality with prompts alone.
Build on infrastructure you can control
I prefer bare metal, on-prem, and open stacks. The moment vendor lock-in, cost, or data sovereignty becomes a problem, the cost of reversing course is simply too high.
Code is a letter to my future self
I choose readable code over excessive abstraction, and verifiable structure over clever tricks — so that anyone, including myself six months from now, can follow it right away.
Build it first, run it first
Every technical choice reflects only what I've actually run in production. I trust experience that has survived production over benchmarks and trends.
How can we work together?
From one-off advisory to long-term partnership — choose what fits your scale
One-off Technical Advisory
- AI adoption, model, and architecture decisions
- System design review and security audit
- 1:1 technical roadmap session
- Deliverable: documented action items
Monthly Retainer
- Ongoing architecture review and PR reviews
- Incident response and on-call advisory
- Team onboarding and technical training
- Priority response and monthly sync meetings
Project Engagement
- AI feature and agent adoption MVP
- Full-stack service development
- Legacy migration
- Infrastructure and security buildout
Philosophy and the Path I've Walked
The attitude and reflection that took shape before the technology
Where the Record Begins
Youngsam.net is a space created to record and share the experience and skills accumulated over a long journey down the single road of development. As time passes, code fades and insights slip to the far side of memory — I want to gather them here, one by one.
Charcoal and the Ant
As a child, I drew a single line with charcoal in front of an ant. The ant treated that line as a boundary and turned back. When I enclosed it with a square, the ant was trapped — on nothing but charcoal dust, not even a wall. Yet the moment it happened to cross the line, the ant no longer hesitated.
"Most of the walls we cannot cross are walls only because we have never once tried to cross them."
The World of Hacking and Code
That realization became an attitude toward life. Captivated by the unknown world of hacking, I began digging into code through the night. I wanted to step, with my own feet, onto the lines others said could not be crossed. The thrill and passion of those days became, beyond technology, a way to understand and express the world.
"At first I only wanted to break into something. But now I've become someone who wants to build something."
Someone Who Designs and Builds
The days of digging into the deepest parts of systems have passed, and now I focus on designing and building on top of that experience. The new possibilities AI opens up, the impact a single line of code has on the world, the moments technology changes people's lives — all of it still fascinates me.
Even now, while running various businesses, I write code every day. Learning a new language still excites me, and I find myself deeply happy living inside the boundless world of possibility that is artificial intelligence.
A Journey That Doesn't Stop
Today, too, I never stop learning — looking back on the path I've walked and calmly designing the path ahead. And still, I am unafraid to step onto the lines someone else has drawn.
"Technology is not a tool but a language, and a developer is someone who speaks their way of understanding the world in code."
Technical Skills
I record only the 118 technologies I've used and run in real work
Programming Languages
AI / Machine Learning
Frameworks & Libraries
Infrastructure & DevOps
Database & Storage
Security & Hacking
Get in Touch
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