upstream
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Alexander Taub and the serious business of being ridiculous
He helped brands understand their followers, built tools for online communities, and co-created Goblintown. Alexander Taub keeps returning to the same question: what makes people want to gather?
Nikos Moraitakis and the upside of bad timing
He came home to Athens as Greece was heading into another election and built software for companies trying to hire. Fourteen years later, the Workable co-founder is still asking which parts of work a computer ought to do.
Alex Vratskides and the arithmetic of a better sentence
A small change in a text message sent Alex Vratskides down a long mathematical road. From Upstream to Persado, he has built a career around a deceptively human question: which words make us respond?
Marco Veremis and the case for staying in the game
He helped build Upstream, watched new companies emerge from its orbit, and became an investor. Now Marco Veremis wants Greek founders to have the money - and the confidence - to keep building.
Mark McClure
Mark McClure is the co-founder and CEO of ResFrac Corporation, a Palo Alto-based company building advanced physics-based simulation software for the energy industry. A Stanford PhD in Energy Resources Engineering, he spent time as an assistant professor at UT Austin before founding ResFrac in 2015. His research on hydraulic fracturing, induced seismicity, and enhanced geothermal systems has earned over 5,800 scholarly citations and an h-index of 38. Under his leadership, ResFrac has grown to serve 60+ exploration and production companies and secured a platform investment from Banneker Partners in 2026. He also advises Fervo Energy on geothermal development.