Principal Mechanical Engineer

42dot•San Francisco, CA

25d•$233,700 - $336,300

About The Position

At 42dot, we are building the high-performance hardware that powers the next generation of autonomous mobility. As the Principal Mechanical Engineer, you will be the technical lead for all mechanical aspects of our compute platforms. Your scope ranges from the precision engineering of ECU enclosures and advanced thermal solutions to the design of the physical infrastructure—fixtures and test benches—that enables our firmware and hardware validation. Beyond design, you are a process architect. You will own the mechanical product development lifecycle, define engineering workflows, and manage the PLM (Product Lifecycle Management) for all mechanical components, ensuring a seamless transition from prototype to volume manufacturing.

Requirements

20+ years of experience in mechanical design and product development, specifically for electronics packaging.
Deep experience in safety-critical industries (e.g., Automotive, Aerospace, or Medical Devices).
Proven track record of leading New Product Introduction (NPI) cycles, taking products from initial prototype through to volume manufacturing.

Nice To Haves

Expert-level proficiency in 3D CAD (SolidWorks, CATIA, or similar) and deep knowledge of manufacturing processes (injection molding, die casting, CNC, sheet metal).
Experience in FEA (Finite Element Analysis) and CFD (Computational Fluid Dynamics) for thermal and structural validation.
Strong understanding of automotive standards for environmental sealing (IP ratings), shock, and vibration.

Responsibilities

Lead Mechanical Design: Drive the design and development of ECU enclosures, fixtures, prototypes, and test benches, and their integration to manufacturing and test infrastructure
Thermal & Environmental: Own the thermal design strategy for high-compute electronics, ensuring reliability under extreme automotive environmental conditions.
Process & PLM: Define and manage the mechanical engineering workflow. Direct the implementation and maintenance of PLM systems to ensure robust version control and documentation for all mechanical assemblies.
Cross-Functional Orchestration: Interface with EE, Firmware, and Quality teams to gather complex requirements and decompose them into actionable milestones and deliverables.
DFX Leadership: Implement rigorous DFM (Design for Manufacturing) and DFT (Design for Test) principles to ensure products are optimized for high-volume production and automated assembly.
Validation & Verification: Design and execute comprehensive product validation plans, including mechanical stress testing, vibration analysis, and thermal cycling.
EMC Integration: Partner with EE teams to design enclosures that meet strict EMC/EMI shielding requirements for safety-critical automotive applications.