Senior Mechanical Engineer - Cryogenic

Rigetti Computing builds full-stack quantum computers - from superconducting qubit devices fabricated in our own foundry to cloud-accessible quantum processors. We are seeking a Senior Mechanical/Cryogenic Engineer to own the mechanical architecture of our quantum hardware systems, from room-temperature infrastructure down to the millikelvin core of our dilution refrigerators.

You will lead the design of the cryogenic signal chain, define mechanical interfaces across thermal stages, and work directly alongside quantum physicists, RF engineers, and systems teams. This is a high-ownership role: you will drive design decisions end-to-end, from concept through qualification, on some of the most technically demanding hardware in the industry.

Key Responsibilities

Cryogenic Hardware Design

• Own the mechanical design of cryogenic hardware from 300 K to millikelvin - thermal anchoring, RF wiring, flex interconnects, coaxial routing, filter housings, and connector packaging across all temperature stages.
• Lead the full design lifecycle: concept, CAD, GD&T drawings, BOMs, tolerance analysis, prototype builds, qualification testing, and manufacturing release.
• Define cryogenic mechanical interfaces and thermal conduction budgets; drive design-for-manufacturability with external machine shops and precision vendors.

Simulation & Analysis

• Perform mechanical, thermal, and vibration analyses independently using COMSOL, ANSYS, or equivalent; use simulation results to drive design decisions and iteration.
• Conduct tolerance stack-up analyses for multi-component assemblies in constrained cryostat environments.

Integration, Leadership & Collaboration

• Lead prototype builds, system integration, and cryogenic bring-up; diagnose integration failures and drive root cause analysis.
• Serve as the mechanical lead in cross-functional programs alongside quantum physicists, RF engineers, and systems teams, mentor junior engineers and lead design reviews.
• Maintain rigorous documentation - CAD models, drawings, BOMs, and revision-controlled design records - within the company PLM system.

Required Qualifications

• B.S. or M.S. in Mechanical Engineering or related field (M.S. preferred).
• 7+ years designing complex mechanical or electromechanical systems with end-to-end hardware ownership.
• Expert-level SolidWorks - large assemblies, GD&T-compliant drawing packages, and DFM workflows.
• Independent proficiency in SolidWorks, COMSOL or ANSYS for thermal and structural analysis.
• Experience with hardware operating in cryogenic, vacuum, or extreme thermal environments.
• Strong ME fundamentals: stress analysis, tolerance stack-ups, materials selection, and failure mode analysis.
• Proven ability to lead technical efforts and collaborate across multidisciplinary teams.

Preferred Qualifications

• Direct experience with dilution refrigerators, cryostats, or sub-Kelvin systems in quantum computing or precision instrumentation.
• Knowledge of superconducting quantum hardware architecture and millikelvin design constraints.
• RF/microwave packaging experience: connector specification, hermetic sealing, and cable routing in cryostats.
• Familiarity with cleanroom protocols, vacuum-compatible assembly, and contamination-sensitive environments.