Josh Mesner

Background

About Josh Mesner

Startup Operator | Builder of Systems & Teams | Trusted Right Hand to FoundersI’ve spent my career at the ground floor of hard tech startups, building the operational backbone while the company scales around me. I'm part of the Operators Guild, the special forces of any company. At AtmosZero, I'm helping reimagine the industrial boiler, making it cleaner, more efficient, and ready for the energy transition. I wear many hats: people ops, compliance, legal, recruiting, finance, IT, whatever it takes to move the mission forward.Before that, I was the 3rd hire at a nuclear energy company in D.C, helping bring Small Modular Reactor (SMR) tech to life. I ran nearly every operational function as we scaled, eventually hiring out full teams to replace me in each area. I was the CEO’s right hand, owning everything that didn’t plug into a reactor.I’ve built HR systems from scratch, negotiated contracts, managed legal compliance, led hiring across all departments, and even shared my story on a podcast. help early-stage and scaling companies turn operational chaos into scalable systems across people, finance, and internal infrastructure—so founders can focus on growth instead of admin.Always open to connecting with other builders, founders, and forward-thinking teams tackling hard problems.