Mechanical / Mechatronics Test Engineer, Dropbox

Zipline builds and operates autonomous delivery systems that move critical goods reliably and safely. Dropbox is our customer-facing package-loading product that integrates mechatronics, sensors, electronics, access control, user interaction, and environmental protection so untrained users can hand off packages to our droids. Failures or slow service at Dropbox directly increase field escalations, maintenance cost, and delivery delays.

As a Senior Hardware Test Engineer on Dropbox, you will own mechanical-heavy test and validation for critical assemblies and system-level behaviors. You will develop the test methods, equipment, automation, and evidence needed to prove that Dropbox meets its functional, safety, reliability, environmental, and lifetime requirements.

This is a hands-on individual-contributor role spanning test strategy, fixture design, instrumentation, experimental execution, data analysis, and failure investigation. You will work closely with design engineers while maintaining independent judgment about test adequacy, product risk, and release readiness.

• Own end-to-end validation of Dropbox mechanisms, structures, enclosures, electromechanical assemblies, and mechanical interfaces from prototype through fleet deployment.
• Translate product requirements, hazard analyses, field conditions, customer workflows, and known failure modes into measurable test requirements and pass/fail criteria.
• Develop verification plans with clear coverage, traceability, sample sizes, margins, acceptance criteria, and exit gates.
• Design, analyze, build, commission, and maintain test stands, fixtures, environmental setups, automated cycle rigs, and representative system test articles.
• Select and integrate instrumentation such as load cells, torque sensors, displacement sensors, accelerometers, strain gauges, thermocouples, cameras, current sensors, and data-acquisition hardware.
• Produce drawings, tolerance analyses, safety reviews, BOMs, assembly instructions, calibration procedures, and maintenance documentation for test equipment.
• Apply free-body diagrams, hand calculations, tolerance analysis, kinematics, fatigue and wear models, and FEA to design test equipment and establish representative loading.
• Develop tests covering structural strength, mechanism performance, high-cycle life, wear, ingress, contamination, corrosion, temperature, humidity, misuse, obstruction, package variation, installation variation, and fault recovery.
• Validate interactions among mechanical hardware, actuators, sensors, electronics, embedded controls, packages, users, and droids.
• Automate test execution, data collection, health monitoring, fault detection, and reporting using Python or equivalent tools.
• Define sample sizes, acceleration factors, confidence levels, and statistical acceptance criteria that produce defensible reliability evidence.
• Correlate bench and accelerated tests with field telemetry, returned hardware, service records, and observed environmental conditions.
• Identify gaps between laboratory tests and field failures, then update test profiles to improve fidelity.
• Lead structured failure investigations using physical inspection, teardown, dimensional measurements, logs, instrumentation, and fault-tree methods.
• Distinguish product failures from fixture, instrumentation, software, setup, and operator-induced failures.
• Partner with Mechanical, Electrical, Embedded Software, Systems, Reliability, Manufacturing, Operations, and Safety to drive failures to root cause and permanent corrective action.
• Establish regression tests that detect hardware and software changes affecting mechanism performance, safety, or reliability.
• Present test evidence, unresolved risks, and release recommendations clearly during design and readiness reviews.
• Work directly with suppliers and manufacturing partners to validate components, tooling, processes, and production changes.
• Mentor engineers and technicians in fixture design, instrumentation, experimental methods, test execution, and failure analysis.
• Improve test throughput, repeatability, automation, lab utilization, and failure-to-answer time.

• Proven ownership of mechanical or electromechanical hardware validation through development, qualification, production ramp, and field deployment.
• Deep hands-on experience designing and building mechanical test rigs, fixtures, instrumented assemblies, and automated cycle-test systems.
• Strong mechanical fundamentals, including statics, dynamics, kinematics, fatigue, wear, materials, bolted joints, tolerance analysis, and FEA.
• Advanced CAD and drawing skills for test equipment, fixtures, interfaces, and released hardware.
• Practical experience selecting, installing, calibrating, and troubleshooting sensors and data-acquisition systems.
• Experience validating mechanisms containing actuators, transmissions, bearings, seals, sensors, PCBAs, harnesses, and embedded controls.
• Demonstrated expertise in experimental design, measurement uncertainty, repeatability, sample-size selection, accelerated testing, and statistical confidence.
• Experience developing automated test and analysis tools using Python or an equivalent language.
• Track record finding root causes for complex or intermittent failures and verifying that corrective actions prevent recurrence.
• Experience testing environmental durability, high-cycle mechanisms, structural loads, abuse conditions, and fault recovery.
• Ability to translate imperfect field data into representative laboratory tests and actionable engineering conclusions.
• Experience working with design teams, suppliers, manufacturing, and technicians to execute test programs under aggressive schedules.
• Clear written and verbal communication, including concise test plans, reproducible reports, and evidence-based readiness recommendations.
• Location and logistics: this role is in person in South San Francisco with regular work in the lab. Travel to suppliers, manufacturers, test locations, and deployment sites is expected based on program needs.
• Periodic off-hours support may be required during critical builds, test campaigns, production ramps, and field escalations.
• Traits: mechanical curiosity, disciplined experimental practice, skepticism of weak evidence, calm troubleshooting, and willingness to remain with a problem until it is understood.

• Delivered repeatable test systems and validation evidence that enabled Dropbox assemblies to meet their reliability and release targets.
• Identified critical failure modes before fleet deployment and verified effective corrective actions.
• Improved correlation between accelerated testing and field performance.
• Reduced test cycle time, manual effort, and failure-to-answer time through better fixtures, automation, and analysis.
• Established reusable test methods that increased validation coverage and supported production and fleet expansion.

Zipline is an equal opportunity employer and prohibits discrimination and harassment of any type without regard to race, color, religion, age, sex, national origin, disability status, genetics, protected veteran status, sexual orientation, gender identity or expression, or any other characteristic protected by federal, state or local laws or our own sensibilities.

We value diversity at Zipline and welcome applications from those who are traditionally underrepresented in tech. If you like the sound of this position but are not sure if you are the perfect fit, please apply!