At WHOOP, we're on a mission to unlock human performance and healthspan. WHOOP empowers members to perform at a higher level through a deeper understanding of their bodies and daily lives. WHOOP is hiring a Senior Mechanical Engineer (Manufacturing Test) to develop the mechanical test fixtures and systems that enable reliable, scalable testing of WHOOP products throughout product development and mass production. You will drive fixture development from early concepts through production deployment, co-developing solutions with our contract manufacturing partners and translating test requirements into robust mechanical designs. Working across Hardware Test, Manufacturing, Electrical, Firmware, and Quality Engineering, you'll provide the technical direction and engineering judgment needed to deliver production-ready fixture solutions. RESPONSIBILITIES • Drive mechanical fixture development for complex manufacturing test applications from early concept through validation, production deployment, and sustaining, partnering closely with contract manufacturers on design and execution • Translate test and product requirements into robust fixture designs, making appropriate tradeoffs between performance, repeatability, complexity, cost, cycle time, and maintainability • Design fixtures directly where appropriate and provide technical direction and design review for solutions co-developed with manufacturing partners • Apply strong mechanical engineering principles including tolerance analysis, GD&T, material selection, datum strategy, alignment, DFM, and manufacturing process selection to review and validate fixture designs • Collaborate with contract manufacturers throughout design, sourcing, fabrication, qualification, and production readiness, including on-site support during NPI and product builds • Lead fixture debugging and root-cause investigations, using structured problem solving and data to resolve issues related to tolerance, alignment, wear, loading, repeatability, and fixture performance • Ensure production-ready CAD, drawings, BOMs, assembly instructions, and fixture specifications are accurately maintained through established PLM and change-control processes • Collaborate across engineering teams to define fixture requirements and drive improvements to fixture design, qualification, maintenance, and development practices QUALIFICATIONS • Bachelor's degree in Mechanical Engineering, Mechatronics, or a related technical discipline • 5+ years of experience designing complex mechanical systems, fixtures, automation equipment, or similar hardware for manufacturing or production environments • Strong mechanical design fundamentals including tolerance analysis, GD&T, material selection, manufacturing processes, fastening methods, and DFM • Advanced proficiency with 3D CAD and engineering drawings; SolidWorks experience is strongly preferred • Experience developing mechanical fixtures or equipment from requirements through prototype, validation, release, and production support • Experience co-developing mechanical systems with contract manufacturers, suppliers, or external engineering partners, including technical direction and design review • Experience creating and maintaining production engineering documentation, revision control, and PLM systems such as Arena • Strong mechanical debugging and root-cause analysis skills, with experience using data to characterize and improve fixture performance • Working knowledge of electrical systems, wiring, instrumentation, and PCBAs sufficient to integrate and debug electromechanical test fixtures • Experience using manufacturing data and statistical methods to evaluate repeatability, variation, and fixture capability; familiarity with SPC is preferred • Strong project ownership, communication, and cross-functional collaboration skills, with the ability to independently drive complex fixture-development projects • Familiarity with Python or other scripting languages for engineering analysis, automation, or debugging is a plus • Ability to travel up to 15%, both domestically and internationally • Strong commitment to leveraging AI tools in day-to-day tasks, ensuring AI-assisted work aligns with the same high-quality standards as personal contributions This role is based in the WHOOP office located in Boston, MA. The successful candidate must be prepared to relocate if necessary to work out of the Boston, MA office. Interested in the role, but don’t meet every qualification? We encourage you to still apply! At WHOOP, we believe there is much more to a candidate than what is written on paper, and we value character as much as experience. As we continue to build a diverse and inclusive environment, we encourage anyone who is interested in this role to apply. WHOOP is an Equal Opportunity Employer and participates in E-verify to determine employment eligibility The WHOOP compensation philosophy is designed to attract, motivate, and retain exceptional talent by offering competitive base salaries, meaningful equity, and consistent pay practices that reflect our mission and core values. At WHOOP, we view total compensation as the combination of base salary, equity, and benefits, with equity serving as a key differentiator that aligns our employees with the long-term success of the company and allows every member of our corporate team to own part of WHOOP and share in the company’s long-term growth and success. The U.S. base salary range for this full-time position is $150,000 - $195,000. Salary ranges are determined by role, level, and location. Within each range, individual pay is based on factors such as job-related skills, experience, performance, and relevant education or training. In addition to the base salary, the successful candidate will also receive benefits and a generous equity package. These ranges may be modified in the future to reflect evolving market conditions and organizational needs. While most offers will typically fall toward the starting point of the range, total compensation will depend on the candidate’s specific qualifications, expertise, and alignment with the role’s requirements.