The team that founded Klaviyo all had experience working in tech companies prior to starting their own. The CTO was previously at RockTech, the Senior Engineer at Performable, and the Lead Engineer at Applied Predictive Technologies. They also all have experience working with software development and testing, with the CTO having interned at Microsoft in this field. All four members of the team went to Harvard University, with three studying physics and one studying astronomy & astrophysics.