About Tacit
We are an early-stage, deep tech startup based in San Francisco, developing innovative hardware that rethinks human-computer interaction. We are backed by General Catalyst, Khosla Ventures, and Greylock Partners, with a founding team from Stanford, BrainGate, Oculus, and Tesla. While we can’t reveal too much just yet, our team is tackling cutting-edge engineering challenges to bring revolutionary products to life.
About the role
We are looking for a Rapid Prototyping Engineer, an engineering generalist who sits at the intersection of R&D and hardware engineering. You'll work closely with our design, electrical, and sensing teams to rapidly design, build, and iterate on mechanical, electrical, and sensor prototypes for novel wearable devices — while also owning the assembly and test fixtures that make those prototypes buildable and repeatable.
This is a hands-on, builder-at-heart role for someone who thrives on ambiguity and enjoys turning a rough concept into a working, testable physical system. You'll be the person the hardware and research teams come to when something new needs to be designed, fixtured, built, and iterated on fast — and when successful, you'll turn those one-off builds into scalable, DFM-friendly processes that support our product ramp from NPI/NTI through production.
What you'll do
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Prototyping & Build
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Rapidly design and fabricate mechanical, electrical, and sensor prototypes to support R&D experiments and engineering development for wearable and consumer-electronics form factors.
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Build end-to-end prototype systems: from concept sketches through CAD, fabrication, wiring, sensor/RF component integration, and validation.
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Develop quick-turn PCBs, flex circuits, wiring harnesses, and cable assemblies for prototype electronics.
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Hands-on soldering and assembly of electrical and sensing circuit components, including delicate flex and fine-pitch work.
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Evaluate and select sensors, actuators, and off-the-shelf components for integration into prototype systems.
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Fixtures & Tooling
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Design, build, and iterate on assembly and test fixtures, jigs, and tooling from the ground up to support novel processes and ensure build quality and efficiency for complex devices and wearables.
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Partner with design engineers to provide DFM/DFA feedback and drive design iterations before problems reach production.
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Build fixtures that improve repeatability, cycle time, and debug visibility for both R&D builds and early manufacturing runs.
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Debug, Troubleshooting & Iteration
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Perform hands-on assembly, troubleshooting, and debugging of electromechanical systems, isolating whether an issue is mechanical, electrical, or process-related.
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Identify and address failure modes specific to wearable hardware (fit, comfort, cable management, contact forces, thermal effects, wear over repeated use).
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Take initiative in driving design iterations, documenting findings, and proposing next steps with minimal supervision.
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Cross-Functional Collaboration
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Collaborate with electrical, RF, mechanical, and firmware engineers to integrate hardware with control systems and test software.
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Support NPI/NTI/R&D efforts, working closely with design and validation teams as products move from early prototype toward production intent.
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Communicate build status, design risks, and recommendations clearly to both technical and non-specialist audiences.
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Document designs, build procedures, and test results to support knowledge transfer and continuous design improvement.
Requirements
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Bachelor's degree in Mechanical, Electrical, Mechatronics Engineering, or a related field.
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2+ years of experience in prototyping, R&D engineering, or hardware development, ideally in wearables, consumer electronics, robotics, or research lab environments.
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Required experience with NPI/NTI/R&D processes, taking hardware from early concept through pre-production.
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Proficiency in CAD software (Onshape, SolidWorks, or Fusion 360) with strong 3D modeling and drafting skills.
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Working knowledge of PCB design and electronics, and comfort with soldering electrical and RF circuit components, wiring, reading schematics, and integrating sensors.
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Hands-on ability to build and troubleshoot electromechanical systems.
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Hands-on expertise with rapid prototyping methods: 3D printing (FDM/SLA), laser cutting, CNC machining, sheet metal fabrication, and manual machining.
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Demonstrated experience designing and building assembly and test fixtures, jigs, and tooling from scratch.
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Excellent project management and cross-functional collaboration skills.
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Strong track record of troubleshooting, debugging, and iterating on designs independently.
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A builder at heart: someone who takes initiative, brings creativity and problem-solving to ambiguous challenges, and can work with minimal supervision.
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Excellent communication skills and comfort operating in a fast-paced, ambiguous environment where requirements evolve quickly.
Strong candidates may have
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Familiarity with wearable or consumer-electronics form factors and the constraints of designing for comfort, fit, and durability against the body.
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Experience with RF or antenna hardware integration and the fixturing challenges specific to RF test and assembly.
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Basic scripting ability (Python) for test automation, data collection, or hardware interfacing.
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Experience supporting builds across EVT, DVT, and PVT stages with contract manufacturers
Success in This Role Looks Like
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Research and design concepts are rapidly and reliably turned into working physical prototypes.
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Assembly and test fixtures enable consistent, repeatable builds across R&D and early production runs.
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DFM/DFA feedback delivered early prevents costly design iterations downstream.
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Cross-functional teams have a trusted go-to person for hands-on build, debug, and fixture needs.
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Prototype learnings and fixture designs translate smoothly into scalable production processes.
Benefits
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Competitive equity package
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Comprehensive medical, dental, and vision insurance
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Company size: 30-50 people
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Unlimited PTO
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Visa sponsorship
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4% 401k matching
Compensation Range: $123K - $139K