Mechanical Engineer, Rapid Prototyping in San Francisco

Energy Jobline ZR; San Francisco (CA); On-site; USD 90,000 - 130,000; Full time

Job summary

Energy Jobline ZR is seeking a Mechanical Engineer focused on rapid prototyping in San Francisco. You will turn ideas into real hardware fast, spinning up 3D printed parts, CNC components, and quick-turn builds to accelerate learning for the team.

You’ll iterate across concepts, optimize for manufacturability, and work closely with lab managers and cross-functional teammates to bring prototypes from sketch to bench in record time.

Qualifications

• Strong, demonstrable CAD skills for rapid part iteration.
• Experience turning concepts into physical hardware quickly.
• Understanding of manufacturability and testability from the first sketch.

Responsibilities

• Design mechanical parts and assemblies in CAD, from concept to build-ready files.
• Plan rapid prototyping spins using 3D printing, CNC, laser cutting, and related methods.
• Choose fastest path to testable prototype with appropriate materials and fidelity as needed.
• Incorporate manufacturability and printability from the outset to avoid costly builds.
• Build, assemble, and bench-test prototypes in lab/shop environments.
• Manage multiple design threads and re-prioritize as test data comes in.
• Document revisions, BOMs, and test notes to preserve traceability.
• Collaborate with electrical, firmware, and product teams to align constraints.

Skills

CAD skills

Rapid prototyping

DFM & DFA mindset

Tools

SolidWorks

Fusion 360

Onshape

3D printing

CNC machining

Laser cutting

Job description

Job DescriptionJob Description

We are helping our client find a Mechanical Engineer, Rapid Prototyping to partner closely with the lab manager to turn ideas into physical hardware fast, spinning up 3D printed parts, CNC'd components, and quick-turn development builds so the team can learn from real prototypes instead of waiting on renderings.

You won't be optimizing a single part for months—in this role, you'll be running many fast iterations across multiple concepts, making calls quickly, and getting hardware into people's hands so the team can decide what's working.

The ideal candidate is someone who is genuinely excellent at CAD, thinks in tolerances and manufacturability from the first sketch, and gets restless if a design sits unbuilt for more than a day.

What you'll do:

• Design mechanical parts and assemblies in CAD, moving quickly from concept sketch to a build-ready file.
• Partner day-to-day with the lab manager to plan and execute rapid prototyping spins—3D printing (FDM/SLA/SLS), CNC machining, laser cutting, and other quick-turn development materials and processes.
• Choose the fastest path to a testable prototype: right process, right material, right fidelity for the question being answered.
• Design for manufacturability and printability/machinability from the outset, catching issues before they cost a build cycle.
• Build, assemble, and bench-test prototypes yourself; you're comfortable in the lab/shop, not just at a workstation.
• Run multiple concurrent design threads and re-prioritize as test results come in.
• Keep tight, lightweight documentation (revisions, BOMs, test notes) so iteration speed doesn't come at the cost of traceability.
• Work closely with electrical, firmware, and product teammates to fold their constraints into the next spin.

Requirements

Qualifications:

• Strong, demonstrable CAD skills (SolidWorks, Fusion 360, Onshape, or similar) — can model complex parts and assemblies quickly and cleanly
• Hands-on experience with 3D printing and CNC machining, including practical knowledge of what each process can and can't do well
• A track record of fast prototyping cycles — you can point to projects where you took a concept to physical hardware in days, not months
• Working knowledge of materials selection (plastics, metals, common development stock) for prototyping vs. production intent
• Comfort in a physical lab/shop environment — you want to be at the machine, not just reviewing output from one
• Strong instincts for design for manufacturability (DFM) and design for assembly (DFA)

Bonus Qualifications:

• Experience with additional fabrication methods (laser cutting, sheet metal, vacuum forming, urethane casting)
• Basic GD&T and tolerance-stack fluency
• Prior experience in a startup, robotics, hardware R&D, or similar fast-iteration environment
• Familiarity with PDM/version control for CAD files