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 As a Senior Software Engineer, you will play a pivotal role in the development of advanced, general-purpose robots designed to operate in human environments and work with human tools. This position demands a high degree of ownership and responsibility, driving projects from conception through to completion, ensuring that Apptronik’s robots perform precisely and reliably in real-world scenarios. You will be responsible for building the software that runs on our on-board computer to enable real-time control, seamless integration of robot data and models, and effective fault detection, diagnostics, and recovery. ESSENTIAL DUTIES AND RESPONSIBILITIES or KEY ACCOUNTABILITIES * Deliver production-grade real-time C++ software infrastructure * Integrate low-level firmware data with high-level controls logic over real-time task graphs * Implement and tune state estimation (IMU, kinematic, odometry fusion) and diagnostic monitors that map sensor faults to DTCs * Characterize and improve the quality of robot kinematics, estimation, and actuation * Bring up new robot embodiments * Integrate learned policies (RL locomotion / motion imitation) into the real-time controls stack * Perform root-cause analysis for complex hardware-software integration issues * Develop API for controls and autonomy systems to interact with robot hardware and simulation * Maintain comprehensive and accurate architecture and design documentation, including HIL and simulation test coverage * Deliver reliable software through code reviews, continuous integration, and automated testing * Represent and lead with Apptronik's core values: CHIPC - Curiosity, Humility, Integrity, Passion, Creativity SKILLS AND REQUIREMENTS * Technical Skills: Strong modern C++, OOP skills, multi-threading, and Linux application development * Deep knowledge of robotics fundamentals (kinematics, dynamics, controls, estimation, and system identification), with bonus points for hands-on experience with floating-base dynamics, contact/constraint modeling, or sensor fusion * Understanding of rigid-body motion and frame transformations * Comfortable in CMake + colcon ROS2 workspaces * Familiarity with at least some of: MuJoCo, Drake, Eigen, ROS2, Flatbuffers, BehaviorTree.CPP * Experience leading hardware-in-the-loop or simulation-based testing of control software * Familiarity with software testing methodologies and version control (e.g., Git) * Strong communication skills and familiarity with Agile processes (sprint planning, design/code reviews) EDUCATION and/or EXPERIENCE * Education: BS, MS, or PhD in relevant fields (Computer Science, Robotics, Electrical Engineering, etc.) * Experience: 5+ years of robotics software development 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. The annual salary range is $215,000 - $230,000.     *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.