← Back to Jobs
Full time
Manufacturing
BEBecoming logo

Machinist / Prototype Fabrication Engineer

BecomingSan Francisco, California🇺🇸United StatesPosted Oct 22, 2026

Quick Overview

Seniority
Mid Senior
Employment type
Full Time
Work mode
On Site
Location
San Francisco, California, United States
Posted
13 hours ago
AssemblyCADCAMCNC

Job Description

About Becoming

Becoming is building a new technology platform at the intersection of developmental biology, engineering, and AI.

Our work requires highly customized hardware. We are looking for an exceptional Machinist / Prototype Fabrication Engineer to help us build it.

The Role

You will work directly with Becoming's engineers and scientists to rapidly turn designs into physical hardware.

This is primarily an R&D and prototyping environment rather than conventional production manufacturing. You should enjoy rapid iteration, unusual engineering challenges, and working closely with the people designing and testing what you make.

What You'll Do

  • Machine precision components for experimental hardware.
  • Operate CNC mills, lathes, and manual machining equipment.
  • Build custom fixtures, jigs, adapters, enclosures, and experimental components.
  • Work from CAD, engineering drawings, sketches, and early-stage concepts.
  • Advise engineers on manufacturability, tolerances, materials, and fabrication approaches.
  • Rapidly modify components in response to experimental results.
  • Develop machining strategies for unusual geometries and low-volume parts.
  • Inspect components and verify critical dimensions.
  • Support assembly, troubleshooting, repair, and modification of experimental hardware.
  • Help build a world-class internal rapid-prototyping capability.

Must Have

  • Have substantial hands-on machining experience.
  • Are highly capable with CNC milling and/or turning.
  • Are comfortable with manual mills and lathes.
  • Can independently take a component from drawing or CAD through fabrication.
  • Understand GD&T, tolerancing, fits, surface finishes, and inspection.
  • Have strong intuition for manufacturability.
  • Are comfortable working across metals and engineering polymers.
  • Enjoy working directly with engineers in a fast-moving R&D environment.
  • Take exceptional pride in the quality of physical things you build.

Nice to Have

  • CAM programming
  • Multi-axis machining
  • Precision fabrication
  • Scientific instrumentation
  • Medical-device hardware
  • Prototype development
  • Metrology and inspection
  • Welding or other fabrication techniques
  • Experience working in an internal R&D machine shop

What Success Looks Like

Ideas move from CAD to experiment dramatically faster because difficult hardware can be fabricated, tested, modified, and rebuilt under one roof.

  • Competitive salary and meaningful equity depending on experience level
  • Full benefits
  • High-trust, high-ownership environment
  • Rapid growth in scope and responsibility