@ 외주 턴키2026Full-Stack
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AI Product Engineer
★ Case 04 / 5Product Engineer Donghyun Kang
Samsung Fire Storybook
A contract where what stayed afterward was not a person — it was a system.
외주 턴키Full-Stack2023.02 ~ 2023.03
── The mission as given ──
“Build the design system and Storybook component library for Samsung Fire's direct service.”
01.Discover
Solo full-stack on a turnkey contract. When the schedule ended, everything ended.
A turnkey schedule, a single full-stack person, a one-off engagement that ended when the calendar ran out. I could have just shipped a handful of components and walked away.
If it ended that way, someone would have to come back the same way every time a new page was added. The real ROI of the contract was a system staying behind, not a person — that recognition was the starting line for the whole job.
Field notes
Note 01
A one-shot turnkey contract
When the schedule ends, what stays in the client's hands is just the library.
Note 02
Solo full-stack
The same person runs both component coding and page application.
Note 03
Built Storybook alongside the code
A way to hand off to the next person through documentation, not raw code.
02.Build with AI
So the system remains after the person leaves.
Decision 01
Componentize the UI
Shaped common UI — Button, Form, Modal — into variant + props. The next developer can reuse them by changing props alone.
Decision 02
Handoff through the Storybook catalog
Documented props, variants, and per-state cases as a visual catalog. Handed off to the next person through docs, not raw code.
Decision 03
Library ↔ service application loop
Did not just build the library — applied it directly onto live service pages. Cases that misaligned during application went back into the library.
tradeoffClean library abstractions vs. the variety of real service requirements
03.Prove with metrics
Only what remained.
New-page build time
−50%+
Assembled from the library
Storybook catalog
Built
Props and variants documented
Designer ↔ developer
A shared language
Visual sharing through Storybook
After the contract
An asset that stayed
The next page still uses the same library
What this case is really about
“An engineer who, even on a one-shot contract, codes so a system remains after the person is gone.”
Define
Reframed the brief from "ship a one-off set of components" into "leave behind a reusable library."
Build
Modular components, a Storybook catalog, and a cycle of applying them straight into the live service.
Prove
New-page build time cut by 50%+. The next developer could work off the library alone.
Linked principlesSystem-FirstHandoff-Ready
More work
