Lead Mechanical Engineer, Data Center Design

About Fluidstack

At Fluidstack, we build the compute, data centers, and power that will fuel artificial superintelligence. We work with Anthropic, Google, Meta, AMI Labs, and Black Forest Labs to deploy gigawatts of compute at industry defining speeds. We are investing tens of billions of dollars in US infrastructure. In 2026, we will deploy 1GW. In 2027, 10GW.

Our team is small, fast, and obsessed with quality. We own outcomes end-to-end, challenge assumptions, and treat our customers' problems as our own. No task is beneath anyone here.

There are a few thousand people who will shape the trajectory of superinteligence. Come and be one of them.

About The Role

The Lead Mechanical Engineer is a senior technical leader within FluidStack’s Design and Engineering team. You will define the mechanical cooling strategy and own the programmatic design from chip to chiller across a multi-site, multi-state portfolio of some of the world’s largest AI data centers.

This is an owner/developer role. You will set the technical direction for how FluidStack cools tens of thousands of GPUs – spanning air-cooled and liquid-cooled architectures, chilled water systems, heat rejection, and in-row/in-rack thermal management. You will define the requirements for modular, prefabricated mechanical assemblies designed around rapid deployment and compute-refresh flexibility. You will manage a growing mechanical engineering team and coordinate across electrical, controls, structural, and construction disciplines to deliver cooling infrastructure at unprecedented speed and scale.

We recently announced a $50 billion computing infrastructure partnership with Anthropic, building custom data centers in New York and Texas with more sites to come. This role will shape the mechanical systems that make that possible.

Responsibilities

Mechanical Strategy & Standards

• Define and own FluidStack’s mechanical cooling strategy across the portfolio – from chip-level thermal interfaces through CDU/coolant distribution, chilled water plants, and heat rejection to atmosphere.

• Develop and maintain the mechanical basis of design, master specifications, standard drawings, and sequence of operations for all cooling systems.

• Drive key architectural decisions: coolant chemistry (e.g. clean PG25 circuits), chiller topology (air-cooled vs. water-cooled centrifugal), CDU elimination strategies, and medium-voltage chiller integration.

• Lead innovation on energy efficiency – free cooling, water-side economizers, waste-heat reuse – targeting best-in-class PUE and WUE across all sites.

• Establish thermal and hydraulic design criteria for high-density GPU deployments (75–150+ kW/rack) spanning direct liquid cooling, rear-door heat exchangers, and hybrid air/liquid architectures.

• Drive innovation and technology development across the mechanical and cooling discipline.
  

Modular Construction & Prefabrication

• Define the requirements for modular, prefabricated mechanical assemblies – including hot-aisle containment cooling units, chiller skids, pump packages, and piping modules – designed for rapid site deployment with minimal field interfaces.

• Collaborate with manufacturing and procurement to evaluate emerging cooling technologies and manufacturing partners – including 800VDC chiller platforms, CO₂-based systems, and integrated chiller/dry-cooler packages.

• Work with BIM and structural teams to ensure prefab mechanical modules integrate cleanly into the base-build design, with fabrication-ready models and coordinated BOMs.
  

Multi-Project Design Delivery

• Own mechanical design delivery across multiple concurrent data center programs – from concept through IFC, coordinating with external MEP consultants and internal discipline leads.

• Review and enforce mechanical deliverable quality at 30/60/90/IFC milestones; manage RFIs, design changes, and value engineering during construction.

• Produce and maintain project-specific mechanical documentation: P&IDs, equipment schedules, valve schedules, piping plans, cooling yard layouts, and pump room arrangements.

• Support factory acceptance testing, site quality inspections, and commissioning of mechanical systems including chilled water loop flushing, passivation, and hydraulic testing.

• Conduct CFD modeling and thermal capacity planning to validate airflow, pressure drop, and temperature targets for each deployment.
  

Team Leadership & Vendor Management

• Build and manage a mechanical engineering team – set priorities, mentor engineers, and create a culture of technical rigor and speed.

• Manage relationships with chiller, pump, dry cooler, and coolant distribution vendors; drive competitive procurement and hold suppliers accountable on lead time, quality, and performance.

• Represent FluidStack’s mechanical interests in cross-functional forums with electrical, controls, construction, operations, and customer engineering teams.

• Interface with customer technical teams on cooling requirements, thermal specifications, and rack-level integration for GPU and TPU deployments.

Basic Qualifications

• B.S. in Mechanical Engineering or equivalent technical discipline.

• 10+ years of experience designing mechanical/cooling systems for data centers, with significant exposure to hyperscale or high-performance computing facilities.

• Deep technical knowledge of chilled water systems, air-cooled and water-cooled chillers, direct liquid cooling, and heat rejection plant design.

• Experience leading or managing a mechanical engineering team and directing external MEP consultants through a full design lifecycle.

• Working command of ASHRAE TC 9.9 thermal guidelines, liquid cooling best practices, and relevant mechanical codes (IMC, ASME, NFPA).

• Demonstrated ability to develop and enforce design standards, basis of design documents, and master specifications across a multi-site portfolio.

• Strong vendor network and procurement experience across chillers, pumps, piping, and cooling distribution equipment.

• Willingness to travel to project sites across the US (estimated 20–30%).

Preferred Qualifications

• Professional Engineer (PE) license or Chartered Engineer credential.

• Direct experience with modular or prefabricated mechanical system design and off-site manufacturing coordination.

• Hands-on CFD experience (6SigmaET, Ansys Icepak, Flotherm) and proficiency with Revit/BIM workflows.

• Experience with medium-voltage (4.16 kV+) chiller applications and 800VDC power distribution architectures in data centers.

• Background in owner/developer-side roles (vs. pure consultant or EPC) with direct accountability for system performance and reliability.

• Experience commissioning large-scale chilled water plants, including chemical treatment, flushing programs, and hydraulic balancing.

• Familiarity with FM Global requirements for mechanical systems in mission-critical facilities.

• Exposure to AI/HPC-specific cooling challenges: high rack densities (75–150+ kW), GPU thermal management, and compute-refresh-ready infrastructure.

Benefits

• Competitive total compensation package (cash + equity).

• Retirement or pension plan, in line with local norms.

• Health, dental, and vision insurance.

• Generous PTO policy, in line with local norms.

The base salary range for this position is $250,000 - $300,000 per year, depending on experience, skills, qualifications, and location. This range represents our good faith estimate of the compensation for this role at the time of posting. Total compensation may also include equity in the form of stock options.

We are committed to pay equity and transparency.

Fluidstack is an Equal Employment Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, national origin, sexual orientation, gender identity, disability and protected veterans’ status, or any other characteristic protected by law. Fluidstack will consider for employment qualified applicants with arrest and conviction records pursuant to applicable law.

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