Founding Engineer - Shoulder

Role details

Full-time (an early engineering hire, not a company co-founder)

What you'll actually own

You are the engineer who owns the shoulder problem end to end. You know shoulder replacement cold, and you build. You take the hard, messy questions about how a shoulder actually moves and behaves during surgery, and you turn them into real hardware, real fixtures, and real experiments that answer them.

You define what the product needs to sense and prove, then you go build it and test it against the bench and the cadaver, not a slide. The best solutions here are creative and simple at the same time, and finding that combination is the job. If Zooly's shoulder product ships, it's because you personally figured out the sensing, designed the tests that made it credible, and drove the technical decisions that got it there.

Where the business is 12 months after you join

If this hire goes the way we intend, one year from now:

• Zooly has a shoulder product concept that is real: sensing strategy defined, prototypes built, and validated on the bench and in cadaver labs, not just described on paper.
• The clinical rationale for the core shoulder features is proven out with surgeons, so we know what we are measuring, why it matters, and that it holds up when a real surgeon uses it.
• The technical and clinical evidence needed for our FDA path on shoulder exists because you built the tests and generated the data behind it.
• Surgeons, strategic partners, and investors take the shoulder product seriously because there is working hardware and independently measured results to show them.

About Zooly

Zooly Labs is on a mission to make advanced surgical guidance more accessible for joint replacement surgery. Joint replacement can restore mobility and quality of life, yet surgeons often have limited objective information during the procedure to assess joint behavior and guide decisions. We build AI-guided technology that combines intelligent sensing, real-time data, and decision support with familiar surgical workflows and standard instruments, without large capital equipment.

We are an early-stage company building a scalable platform across hip, knee, and shoulder.

How we work at Zooly

Patient-driven. Design-obsessed. We're an in-person team of curious, driven people who care about getting the details right, because there's a patient on the table counting on us. A few beliefs shape how we build, and this role lives at the center of them.

• The patient is why. Behind every procedure is a person counting on the people who built the tools. That is what keeps our standards high and our design work honest.
• Act like an owner. We take responsibility for our decisions and how we communicate, we think long-term, and we bias toward action.
• Master your craft. We invest in people who go deep. There is no ceiling that forces a great engineer or designer into management to advance. Go as far into your craft as you want.

What this role is really like

This is hands-on, and it moves fast. One day you are cutting fixtures and wiring up sensors on the bench, the next you are in a cadaver lab watching how a shoulder actually behaves and taking notes that will change the design by Friday. You will build things that do not work yet, break them, and build them better.

It is a small early-stage team, so there is no one to hand the hard part to. That is the appeal for the right person and a dealbreaker for everyone else. If you want a defined lane and a stable roadmap, this will frustrate you.

If you want to own a hard problem and see your work reach a surgeon, this is exactly it.

What you'll do

• Own the shoulder application across Zooly's Sense, Solve, and Go capabilities, from early concept and feasibility through verification, validation, and readiness.
• Run surgeon design sessions, cadaver and design labs, and bench studies, then turn what you learn into concrete design changes.
• Translate what a surgeon needs during a shoulder procedure into real requirements, test protocols, and buildable product concepts.
• Define what the product should measure: the clinically meaningful outputs, the ground truth to compare against, and the acceptance criteria that make a result credible.
• Design and build the prototypes, sensing hardware, and bench fixtures, and test them until the data holds up.
• Build the technical and clinical evidence behind our shoulder FDA path, including intended use, product claims, verification and validation data, and responses to regulatory questions.
• Support risk management, design controls, and human factors work alongside our regulatory and quality partners.
• Show the shoulder product to surgeons, strategic partners, and investors with working hardware and real results behind it.

What you need to be able to do

These are capabilities, not credentials. If you can do these things, we want to talk regardless of how many years it took you to get here.

• You have personally taken a device from an unmet clinical need through prototyping, verification and validation, and design transfer toward clinical or regulatory readiness.
• You know shoulder orthopaedics well enough to hold your own with surgeons: anatomy, biomechanics, implant and instrument workflows, and where things actually go wrong.
• You can turn surgeon feedback into measurable requirements, design inputs, and acceptance criteria that an engineer can build and test against.
• You can plan and run cadaver labs, design labs, and bench studies, including the experimental design, the data interpretation, and the follow-up that changes the design.
• You can define clinically meaningful metrics and ground truth for sensor- or algorithm-based products, and design the validation that proves them.
• You work fluently inside medical-device design controls, risk management, and verification and validation in an FDA-regulated or ISO 13485 environment.
• You can carry the technical and clinical content of an FDA path yourself: intended use, product claims, validation evidence, and clear answers to hard regulatory questions.
• An advanced degree in biomedical engineering, biomechanics, robotics, mechanical engineering, or a related field is common for this work, but the ability to do the things above matters far more than the diploma.

What would make you a strong fit

• Direct work in anatomic or reverse shoulder arthroplasty, shoulder biomechanics, stability and impingement, implant positioning, navigation, or shoulder instrumentation.
• Experience with surgical navigation, smart instruments, intraoperative sensing, digital surgery, or AI-enabled decision-support products.
• You have established clinically meaningful performance metrics, ground truth, and validation strategies for sensor- or algorithm-based products.
• You have supported FDA 510(k) strategy, pre-submission activities, clinical evidence generation, human factors and usability, or product claims.
• A track record of product launches, patents, peer-reviewed publications, clinical collaborations, or moving technology from research into a real product.
• You are comfortable in a startup: rapid iteration, ambiguity, tight resources, and getting your hands dirty on the hard problem.
• You are hands-on with IMUs, force, pressure, or strain sensors, wireless modules, and data-acquisition systems, and you can use Python, MATLAB, or C/C\+\+ to analyze experimental data and automate your own workflows. Familiarity with machine learning workflows (data prep, training, validation, tools like scikit-learn, PyTorch, TensorFlow, or Pandas) is a plus.

How this role works with the rest of the team

You own the shoulder problem and its clinical interpretation, and you work shoulder to shoulder with the engineer who owns system architecture and the engineer who drives hands-on prototype and design-lab execution. Alongside them, you lean on Zooly's shared engineering team for software, electrical, embedded, mechanical, data, and test capabilities, which is exactly what lets you go deep on the shoulder problem instead of building everything from scratch. You also work directly with the surgeons, regulatory, and quality people who keep the work honest and moving toward a real product.

Stay curious

We hire curious people. The kind who took things apart as kids and never stopped asking how things work. If that sounds like you, we'd love to meet.

The fine print

Zooly Labs is an equal opportunity employer and evaluates candidates without regard to legally protected characteristics. Responsibilities will evolve as the company and product portfolio grow. This is an in-office role in Boulder, CO. The role may require occasional travel to design labs, surgeon meetings, suppliers, cadaver studies, or clinical sites. Compensation, equity, benefits, and work-authorization details will be discussed directly.