Apptronik is a human-centered robotics company developing AI-powered robots to support humanity in every facet of life. Our flagship humanoid robot, Apollo, is built to collaborate thoughtfully with people, starting with critical industries such as manufacturing and logistics, with future applications in healthcare, the home, and beyond. We operate at the cutting edge of Applied AI, applying our expertise across the full robotics stack to solve some of society's most important problems. You will join a team dedicated to bringing Apollo to market at scale, tackling the complex challenges like safety, commercialization, and mass production to change the world for the better. JOB SUMMARY Apptronik is seeking a Senior Mechanical Engineer – Structural Simulation to serve as part of the technical team responsible for the structural integrity, mass optimization, and dynamic performance of our humanoid robot, Apollo. In this role, you will perform simulations that allow us to move from "concept" to "validated hardware" with minimal physical prototyping cycles. As a senior engineer, you will tackle the most complex physics problems such as impact dynamics, high-cycle fatigue in high-DOF joints, and multi-body dynamics, ensuring that every gram of material on the robot is earning its keep. You will bridge the gap between high-level autonomous behaviors and the physical limits of the machine's skeleton.   ESSENTIAL DUTIES AND RESPONSIBILITIES or KEY ACCOUNTABILITIES ● Predictive Engineering: Help guide the culture from "design and then check" to "simulation-driven design" where analysis informs the initial architectural trade-offs of the robot. ● Standardization: Support the development of company-wide standards for material models, boundary conditions, and safety factors for humanoid-specific load cases (e.g., falls, high-speed walking, and heavy lifting). ● Non-Linear & Dynamic FEA: Perform analysis of complex, non-linear events such as high-velocity impacts (robot falls) and transient dynamic loads during rapid limb acceleration. ● Fatigue & Life Prediction: Perform fatigue life models for the robot’s primary structure. Predict the lifecycle of components subjected to millions of gait cycles using advanced fracture mechanics and durability analysis. ● Mass Optimization: Utilize topology optimization and generative design to drive aggressive mass reduction across the limbs and torso while maintaining required stiffness-to-weight ratios. ● Test/Sim Correlation: Work closely with the Hardware Integration and Test team to design physical experiments (strain gauging, modal testing, drop tests) that validate and "tune" your simulation models. ● Material Characterization: Lead the efforts to characterize specialized materials—from high-strength aerospace alloys to advanced composites and 3D-printed lattices—to ensure accurate simulation inputs. ● Mentorship: Act as a technical mentor for junior engineers, providing "deep-dive" design reviews and solving the "impossible" physics bottlenecks.   SKILLS AND REQUIREMENTS ● Education: B.S. or M.S. in Mechanical Engineering, Aerospace Engineering, or a related field with a focus on Computational Mechanics. ● Experience: 4+ years of experience in structural simulation and mechanical design, with a proven track record of shipping complex, high-performance electromechanical products (Robotics, Aerospace, or Automotive). ● Software Mastery: Proficiency in industry-standard simulation suites (e.g., Ansys, Abaqus, SimCenter). ● Physics Depth: Solid mechanics, vibration (vibration, shock, and modal analysis), heat transfer, and multi-body dynamics. ● Humanoid Context: Specific experience with high-speed moving mechanisms or "lightweighting" structures for mobile platforms is highly preferred. EDUCATION and/or EXPERIENCE ● B.S. or M.S. in Mechanical Engineering, Aerospace Engineering, or a related field with a focus on Computational Mechanics. ● At least 4 years of experience in structural simulation and mechanical design, with a proven track record of shipping complex, high-performance electromechanical products (Robotics, Aerospace, or Automotive).   PHYSICAL REQUIREMENTS ● Prolonged periods of sitting at a desk and working on a computer ● Must be able to lift 15 pounds at times ● Vision to read printed materials and a computer screen ● Hearing and speech to communicate     *This is a direct hire.  Please, no outside Agency solicitations.  Apptronik provides equal employment opportunities to all employees and applicants for employment 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.