Nikon SLM Solutions names two co-presidents as CEO Sam O'Leary moves to advisory board
Nikon SLM Solutions is splitting its top job in two. CEO Sam O’Leary moves to the company’s Supervisory Board during Q4 2026, and Jan-Niklas Thielmann (Chief Financial and Administration Officer) and Simone Castellani (Chief Technology and Engineering Officer) become Co-Presidents, both joining the Management Board.
| Role | Name |
|---|---|
| Co-President (was CFO/CAO) | Jan-Niklas Thielmann |
| Co-President (was CTO/Chief Engineering Officer) | Simone Castellani |
| Moving to Supervisory Board | Sam O’Leary |
| Supervisory Board Chairman | Hamid Zarringhalam |
Thielmann and Castellani take over day-to-day operations; O’Leary stays on to “help guide strategy and support customers and partners,” according to the company. Zarringhalam, who is also General Manager and CEO of Nikon Advanced Manufacturing, continues to oversee Nikon SLM as a unit of that larger Nikon business.
The timing lines up with Nikon SLM’s MACHX launch at Formnext, which Castellani flagged as the company’s immediate focus: “our focus is on helping customers turn ambitious ideas into repeatable production.” Zarringhalam framed the move as continuity rather than a pivot, saying Thielmann and Castellani “know this company, its customers and its technology inside out.”
O’Leary’s stated reason for leaving the CEO chair is personal rather than business-driven: he says he’s using the move to pursue “a long-held passion in the professional sports and entertainment industry,” while staying on the Supervisory Board.
Nikon SLM has not published a start date for Thielmann and Castellani beyond “during Q4, 2026,” nor said whether O’Leary retains any equity or compensation tied to the Supervisory Board seat. The company’s own framing, that this is “about continuity” and “comes from a position of strength,” is asserted rather than backed with revenue, headcount or order figures in this announcement.