Sietse van der Post is Co-Founder and CTO at Invisix Measuring Systems, a deep-tech semiconductor metrology startup spun out of ASML in 2025 and headquartered in Eindhoven, Netherlands.

Sietse holds a PhD in Physics from the University of Amsterdam (2008-2013) and spent over a decade at ASML advancing soft x-ray metrology research, also bringing experience from AMOLF and Capital Tool Company.

Alongside co-founder Christina Porter, Sietse is commercialising a decade of Nobel Prize-linked soft x-ray R&D, a level of technical de-risking rare for a seed-stage hardware company.

At Invisix, Sietse leads the technical development of soft x-ray measurement systems using High Harmonic Generation (HHG), combining proprietary reconstruction algorithms and machine learning to reconstruct 3D chip structures non-destructively.

In 2023, the Invisix team publicly demonstrated its technology with Intel and imec, successfully measuring next-generation gate-all-around transistor architectures, and in 2026 raised an oversubscribed EUR 20 million Seed round backed by Hitachi Ventures, Transition Ventures, imec.xpand, Doosan Investment, and Samsung.