HeaukJun Yoo
I'm a full-stack engineer in Seoul.
I started my career at a network security company, on the engine backend — on-premise and cloud proxy security servers written in C and Go. All of a company's traffic passed inline through them, and for close to four years I worked down at that level, in Linux and networks.
Then I moved to startups and took on backend and infrastructure. Mostly that meant keeping servers up while the app grew, but I ended up building a lot of client features too. Once I was wiring in payments and ads, I started building with the business in view — watching the revenue numbers and deciding what to build next off them. These days that extends to which numbers to watch, and when to stop.
I keep notes here on problems I ran into at work. Probably more about the ones that went wrong than the ones that went well.
Work
- Yatav — Full-stack Dev Lead
I lead a team of five engineers and a designer at a 17-person startup. Since the pivot into AI security, my work has been turning the product into something sellable and operable.
- Levit — Software Engineer
I was the only engineer on a commerce app's app-tech squad, handling three products alone from the React Native client through the backend.
- Hilokal — Full-stack Engineer
Backend and infrastructure for a real-time voice app while it went from 150K to 2M users. I built client features too, and worked on ads and subscriptions.
- Monitorapp — Backend Engineer, Security Engine
Built on-premise and cloud proxy security servers (SWG) in C and Go, carrying all traffic inline for companies of a few thousand to ten thousand people.