Founding Simulation Engineer (C++)

Description

Founding Simulation Engineer (C\+\+) Type: Full\-time · Founding team Location: Remote\-first, async\-first Compensation: Competitive salary \+ founding\-team equity About Nonlimi Nonlimi is building a cloud\-native simulation platform for testing and validating AI agents for autonomous systems — ground robots, drones, and autonomous vehicles. We're building the simulation infrastructure that robotics startups can't afford to build themselves. Our technical foundation: an open\-source ROS2 bridge (Apache 2\.0\), reproducible version\-pinned physics with MuJoCo, and physics\-state projection annotations for exact ground truth. We are pre\-revenue and architecture\-complete, with a deterministic simulation\-and\-validation core already shipped — deterministic physics, a scenario/regression runner, the ROS2 bridge, and an annotation pipeline — now in active design\-partner scoping. The Role You will own the simulation core — the physics engine, sensor simulation, and the bridge between C\+\+ physics and the rest of the platform. This is not a feature team role. The simulation core is the product. Your work includes: * Deterministic physics \+ the regression/replay loop — MuJoCo in deterministic mode (single\-threaded, version\-pinned, \-fno\-fast\-math), plus the bit\-exact replay and baseline\-comparison loop that makes simulation usable as CI. This loop is the core of the product. * Shared\-memory IPC — out\-of\-process ring buffer bridging C\+\+ physics to the platform layer * ROS2 C\+\+ bridge — native ROS2 integration so customers can use standard tooling (rviz2, rosbag, ros2 topic) * Sensor simulation \+ noise/degradation models — LiDAR ray\-casting (MuJoCo mj\_ray today; Intel Embree on the roadmap) and camera are shipped; you'll deepen them and build the sensor\-noise and degraded\-signal models (LiDAR, camera, GNSS\-denied, IMU) that validation work depends on — feeding physics\-state\-projection annotations for exact ground truth * Open\-source Nonlimi Core — your work ships under Apache 2\.0 Over the first year, you'll extend the core — DART for articulated manipulators, USD pipeline integration, and additional physics domains as new verticals come online. What You'll Do First The deterministic core already exists — clone the repo and run nonlimi test scenarios/examples/husky\_basic.yaml \-\-output\-dir ./artifacts to get a pass/fail verdict and a full artifact bundle in about a second. Your job is to own it and take it from prototype to product: harden the deterministic regression/replay loop, and build the sensor\-noise and degraded\-signal models the first design\-partner proof\-of\-concept needs. Early on, you'll help land the first measured sim\-vs\-real correlation result — the evidence that the validation actually predicts hardware behavior. Requirements These are hard gates: * C\+\+ systems engineering, 4–7 years — performance\-critical C\+\+ where memory layout, cache behavior, and undefined behavior were first\-class concerns * Physics engine internals — MuJoCo, Bullet3, PhysX, DART, or Gazebo at the integration level — constraint solver configuration, determinism flags, collision shape management * C\+\+ shared\-memory IPC — POSIX SHM, lock\-free ring buffers, std::atomic with explicit acquire/release/seq\_cst ordering * Non\-determinism debugging — you have found and fixed a case where physics state diverged across runs, across machines, or after a compiler upgrade Nice to Have * MuJoCo C API directly (not just mujoco\-py or dm\_control wrappers) * ROS2 C\+\+ (rclcpp, DDS transport, composable nodes, lifecycle nodes) * pybind11 or similar C\+\+/Python binding experience * Godot 4 or real\-time scene graph experience (Unity, Unreal at the renderer level) * Sim\-to\-real deployment — taken a policy from simulation to a physical robot What We Offer * Competitive salary \+ founding\-team equity — calibrated to seniority and depth of experience * Full architectural ownership — Nonlimi Core is yours to design, build, and evolve * Open\-source impact — you're building simulation infrastructure the robotics community will use * Direct customer access — you'll talk to autonomy startups and robotics labs directly * Remote\-first, async\-first — deep work is the default How to Apply Send us something that demonstrates C\+\+ systems work — a GitHub project, a PR to an open\-source project, a Gazebo plugin, a physics engine integration. A strong resume without a code artifact is harder to evaluate; a mediocre resume with compelling code is easier. After a 30\-minute screening call, we'll send a take\-home exercise: Build a minimal SHM ring buffer: C\+\+ producer, Python consumer. 2–4 hours. We're evaluating memory ordering correctness and your written analysis of where you placed acquire/release semantics and why. ops@nonlimi.com Job Type: Full\-time Pay: From 40,000\.00€ per year Work Location: In person