Principal Operations Engineer, Mechanical — Data Center Operations

Fluidstack is a company that builds the compute, data centers, and power needed for artificial superintelligence. They are seeking a Principal Operations Engineer, Mechanical to oversee the operational mechanical and cooling infrastructure across their AI data center portfolio, ensuring precision execution for thermal conditions and leading site assessments and operational audits.

Responsibilities:

• Serve as the principal operational technical authority for mechanical infrastructure across the fleet, including chillers, cooling towers, CRACs/CRAHs, CDUs (direct-to-chip and immersion), dry coolers, economizers, pumping systems, water treatment, and associated piping infrastructure
• Lead technical and operational site audits across active and pre-activation sites; produce operational health assessments with prioritized findings and own the remediation roadmap through closure with site leadership
• Own mechanical operational readiness for new sites coming online — assess team capability, validate procedures, and personally sign off on operational handover from commissioning to steady-state operations
• Review operational designs for new builds and capacity upgrades; represent the operational point of view in design forums and ensure operability, maintainability, and reliability concerns are surfaced and addressed before they are built in
• Feed structured operational learnings back into the design and manufacturing organization as we shift toward repeatable, productized data center builds; reinforce patterns that work and drive out patterns that have not held up in operations
• Author and approve high-risk MOPs, EOPs, and AOPs; serve as the final technical approver for high-consequence mechanical work across the fleet
• Lead root cause analysis for significant thermal or mechanical events; drive corrective actions through to closure and ensure learnings propagate across all sites
• Contribute to and uphold the mechanical safety program in partnership with EHS, with explicit accountability for refrigerant handling, confined space, LOTO, and high-pressure systems discipline
• Partner with QA/QC during construction to provide an operational perspective on workmanship, installation quality, and pre-energization readiness
• Build and deliver technical training to Field Engineers and operational teams; own the technical curriculum for mechanical content in the campus rotation and training model
• Mentor Field Engineers and rising operational leaders; act as the senior technical voice in operational reviews, incident reviews, and design reviews

Requirements:

• 10+ years of hands-on experience in mission-critical mechanical and cooling systems, with at least 5 years as the senior technical voice on a site, campus, or fleet
• Data center operations experience strongly preferred; central plant, industrial cooling, pharmaceutical, or semiconductor mission-critical experience considered
• Deep working command of chilled water plants, condenser water systems, CDUs and liquid cooling, air handling, refrigeration cycles, and pumping and piping systems — earned in the field, not from a textbook
• Practical command of psychrometric charts, refrigeration cycles, and ASHRAE thermal guidelines for data center environments
• Demonstrated ability to author, approve, and execute high-risk MOPs and EOPs in live critical environments
• A track record of leading root cause analysis on significant thermal or mechanical events and driving corrective actions to closure
• A track record of holding OEMs, service vendors, and contractors accountable — you know how to enforce a standard without burning the relationship
• Strong written communication: operational health assessments, RCAs, procedure reviews, and design review feedback are second nature
• Comfort operating as the senior technical voice across operations, design, construction, hardware, and EHS
• Willingness to travel extensively across the fleet
• Bachelor's degree in Mechanical Engineering or related field
• Direct experience with direct-to-chip or immersion liquid cooling at production scale
• Hyperscale or large colocation operational experience at hundreds of MW+ scale
• EPA 608 Universal certification
• Trade certification or state license in HVAC; PE licensure
• Uptime Institute AOS or equivalent operations credential
• Tier III/Tier IV commissioning leadership experience
• Experience operating across multiple sites or as part of a global fleet operations function
• Experience standing up new sites from commissioning handover through steady-state
• Experience contributing operational requirements into reference designs or productized data center builds