New Start

It’s been over a month since my last post, and I’ve had a busy start at my new role with Viva Republica. You might recognize the company better by its flagship service, Toss—South Korea’s leading fintech platform, serving over 20 million monthly active users. If you’re looking for a U.S. comparison, think of Toss as a blend of PayPal, Robinhood, and SoFi—all in one. As you might guess from the word “Republic” in our name, we have a unique and mission-driven company culture. Toss recently launched its first U.S. engineering office in Los Altos, and I’m honored to be the first hire for this new chapter.

The role of this office could evolve in many directions, but the initial focus is on online advertising—an area I’ve worked in for the past eight years. What excites me most is the opportunity to explore the "true" value of performance advertising—where publishers and advertisers can both win, when properly aligned.

My previous company mastered ad performance at the demand side. But I’ve always been curious about the supply (publisher) side—especially the parts that are often overlooked or opaque. I’ve wanted to dive into the full end-to-end experience, and Toss offers a rare opportunity to do just that. It’s not often you find a product-driven company with massive scale and the appetite to explore this space holistically.

Just last week, we held our official office opening ceremony, welcoming many guests and industry friends. I was pleasantly surprised to see strong interest from Bay Area engineers in Toss’s new U.S. presence. As part of the event, I also gave a short session about my career journey as a 50-year-old engineer—sharing the ups, downs, and what still keeps me curious and motivated.