This as-told-to essay is based on a conversation with Andrew Bialecki , the 40-year-old CEO of Klaviyo, based in Boston. It's been edited for length and clarity. I got a BA in physics, astronomy, and astrophysics from Harvard. While in college, I interned at a small division of Microsoft that managed the MSN.com website. After graduating in 2007, I worked at several startups. I reached the point where I realized I had great ideas and wanted to build something of my own. I pulled in a friend who