Senior Simulation Software Engineer

Zipline is scaling the world's largest autonomous drone delivery network—a pioneering Physical AI system—delivering life-saving medical supplies and commercial goods globally. Our commitment to safety and exponential scale demands an industrial-grade virtual test environment, decoupled from physical hardware. That’s the mission of our Simulation team.

We are seeking a Simulation Software Engineer to build and evolve the core infrastructure that validates our entire robotics fleet software. This is not a standard simulation role; it is deep, systems-level software engineering focused on creating high-performance, high-fidelity digital twins that enable deterministic, faster-than-realtime testing of all autonomous safety-critical flight logic, cloud connectivity, and vehicle coordination across thousands of mission scenarios.

This role is absolutely critical for the safety and reliability of Zipline's real-world Physical AI deployment. If you are driven by the challenge of integrating complex flight software with synthetic environments, real hardware, and advanced time-manipulation to rigorously test an autonomous system, we want to hear from you!

• Robotics Infrastructure Framework: Own the universal simulation test automation framework utilized by teams across the organization, including Autonomy, Embedded Systems, Cloud, Ground Software, and Test Engineering, making you a company-wide enabler for rapid iteration.
• Deterministic Core Systems: Architect the core synchronization and control system that drives the simulation's time flow, input generation, and complex scenario orchestration, allowing rigorous validation of full-stack autonomy and emergency workflows.
• Fleet Digital Twins & Virtual Test Environment: Develop a robust, scalable environment for testing real-world failure modes, complex multi-robot fleet behaviors, and system edge cases at scale, eliminating reliance on physical aircraft or hardware for regression testing.
• Synthetic Data Generation: Lead the integration of advanced image sensor and visual autonomy simulation capabilities for verification of closed-loop perception and control software.
• Service Integration Layer: Build and maintain integration layers that connect simulated vehicle components with fake cloud servers and ground station software, creating a true end-to-end system digital twin.
• Performance & Scalability: Lead the transition of our in-house simulation system to Rust, a critical, high-impact initiative focused on dramatically improving speed, maintainability, and long-term scalability of our robotics development cycle.

This is not a niche role within Autonomy—it’s a company-wide enabler.

• The Flight Software team uses simulation to validate onboard mission logic.
  
• The Test team uses it to explore pre-flight conditions and troubleshoot real-world anomalies.
  
• The Cloud team uses it to model server interactions like map updates, delivery instructions, and real-time comms.
• Full system Hardware-In-The-Loop testing framework uses simulation for flight software validation
  
• The Embedded and Ground teams use it to validate system integration, safety cases, and operational resilience.
  
• And the CI/CD pipeline relies on simulation to catch regressions before they ever reach a flight zone.
  

If your passion lies in building infrastructure that unlocks fast, safe iteration across multiple engineering domains, this role is built for you.

• 4+ years of professional software engineering experience in C++ or Rust (Rust experience is a strong plus).
• Deep experience architecting, building, or maintaining complex robotics, aerospace, or distributed systems simulations/digital twins.
• Expertise in concepts like time synchronization, inter-process communication, and determinism within a systems-level or real-time context.
• Applied knowledge of physical modeling and dynamics (mechanics and motion) to support high-fidelity system modeling.
• A passion for building enabling infrastructure and tools that allow Zipline engineers to simulate faster, test earlier, and deploy safer.
• Bonus: Experience scaling simulation in CI, HIL (Hardware-in-the-Loop), or formal verification methods.
• Bonus: Experience with visual autonomy systems for navigation or DAA.

The starting cash range for this role is $180,000 - $225,000. Please note that this is a target, starting cash range for a candidate who meets the minimum qualifications for this role. The final cash pay for this role will depend on a variety of factors, including a specific candidate's experience, qualifications, skills, working location, and projected impact. The total compensation package for this role may also include: equity compensation; discretionary annual or performance bonuses; sales incentives; benefits such as medical, dental and vision insurance; paid time off; and more.