Senior Staff Mechanical Engineer - Electromechanical

Mainspring is looking for a Senior Staff Mechanical Engineer — Electromechanical to lead the design and integration of electrical enclosures, busbars, and cable systems for our next-generation energy platforms. This is a highly visible technical leadership role focused on solving difficult real-world engineering problems across power electronics packaging, harsh-environment durability, manufacturability, and system integration. You’ll help shape core product architecture while working on systems deployed across demanding operating environments ranging from coastal and desert conditions to future megawatt-scale applications. We’re looking for an engineer who understands how electrical and mechanical systems behave in the real world — and can drive robust electromechanical solutions from concept through production.

Responsibilities

Lead the design and development of electrical enclosures, busbars, cable assemblies, and integrated electromechanical systems; Drive packaging decisions balancing thermal performance, vibration durability, EMI considerations, creepage/clearance, manufacturability, serviceability, and cost; Own hardware through the full product lifecycle including concept development, prototyping, validation, production launch, and sustaining engineering; Partner closely with Electrical, Reliability, Manufacturing, Test, NPI, and supplier teams to develop robust hardware solutions; Solve challenging environmental durability problems involving corrosion, outdoor deployment, thermal extremes, and vibration-heavy operating conditions; Lead root-cause investigations for field and test failures and drive corrective actions into production; Mentor engineers through design reviews and technical leadership on complex problems

Requirements

BS or MS in Mechanical Engineering or related field; 12+ years of experience designing electromechanical hardware systems; Proven experience designing electrical or electronic enclosures through production release; Strong background in sheet metal design and mechanical-electrical integration; Experience packaging electrical components such as fuses, contactors, relays, PCBAs, busbars, cables, connectors; Experience in designing systems such as inverters, controllers, fuse systems, batteries, or other power electronics; Understanding of thermal management, vibration, environmental durability, grounding, creepage/clearance, and EMI-related packaging constraints; Experience supporting validation, testing, manufacturing launch, and sustaining engineering; Proficiency with SolidWorks and PLM systems

Nice to have

Busbar design experience; HV power systems experience; Cable harness and routing design experience; Experience with corrosive or outdoor deployment environments; Familiarity with FEA tools such as Ansys; Background in EVs, power electronics, energy systems, industrial equipment, or ruggedized hardware systems