Inside Plus: Hyoungju Seo, Staff Software Engineer – Planning
One measure of how much engineers love their jobs is the amount of time they spend outside of work grappling with the technical problems they are trying to solve.
By that metric, Hyoungju Seo is passionate about his job at Plus. “When I’m driving in my own car, I think about the various algorithms and how to implement and test them. When the results are what I expected, it feels really rewarding.”
Seo attended Seoul National University and obtained a Master’s Degree in aerospace engineering from Stanford. He has been with Plus since 2019.
1. You studied aerospace engineering in school and now work in autonomous driving. Tell us about that transition.
When I was in elementary school, I dreamed about going into space. But being an astronaut is not an easy job, and Korea doesn’t have the technology to send our people into space. So I decided to focus on making the technology that would allow people to go into space.
After graduating from Seoul National University, I wanted to experience other cultures and gain a global perspective, so I came to grad school at Stanford. Aerospace systems are autonomous systems, so working on autonomous vehicles at Plus is a great fit for what I’ve always wanted to do.
2. What drew you to Plus?
I’ve always wanted to work in autonomous driving. It’s one of the toughest technical challenges of our generation, and that excites me because I enjoy solving complex problems. Trucking is the perfect application of driverless tech—it’s a tough job yet so critical to the economy. Issues like long hours, safety risks, and growing driver shortage can all be addressed by autonomous trucks.
I was drawn to Plus because of its practical, heads-down approach to technology development. Three of the founders are Stanford-trained engineers and serial entrepreneurs with a track record of launching successful tech products, so I believe we’ll build an autonomous trucking product that customers will actually want to pay for.
3. How has your role evolved over the past 5 years at Plus?
I work on motion planning, which sets the driving path for our vehicle. After taking in all information on what’s happening on the road through our sensors, my team trains our system on where to go next based on that understanding.
Over the past five years, my role has grown alongside the industry’s shift from AV1.0 to AV2.0. Initially I spent most of my time writing codes and focused on foundational algorithms, I’m now leveraging sophisticated neural networks and training AI models to enable our system to handle complex scenarios naturally across different geographies and road conditions.
4. Looking back on your 5+ years with Plus, what are some of the most rewarding aspects of your job? What project or achievement are you most proud of?
Being a part of our program with Hyundai Motors has been exciting. Seeing our Level 4 technology in action with the biggest vehicle manufacturer in Korea (and one of the world’s largest) feels like a full-circle moment because it connects me back to my home country.
Beyond this program, it’s incredibly fulfilling to see our autonomous truck navigate complex scenarios like a human driver with the AI models that I have implemented. I get to see it through from initial concept to a fully functional feature, where it’s performing safely and reliably in diverse conditions.
5. How would you describe the Plus workplace culture?
The company always welcomes new ideas. I’ve always felt encouraged to bring fresh perspectives to the table and explore new approaches. It’s been a huge part of why I’ve stayed here for over five years.
6. Share an interesting fact about yourself.
All South Korean men have to do military service for two years. You can choose to apply to the police, Army or Navy. I applied for the police, and the job was guarding the former President’s house. We guarded 24 hours a day, and I worked 6-8 hours a day. It was quite boring [laughs].
