Software Engineer, Control Systems At Lendurai , we enable unmanned aerial vehicles (UAVs) to operate independently of global navigation satellite systems and radio control, using computer vision and machine learning. We partner with multiple UAV manufacturers to deliver cost-effective capabilities to public sector and defence customers. Our team has deep experience in aerospace engineering, defence tech, and autonomous systems, with backgrounds at companies like Bolt (EE), Open Cosmos (UK), and Starship Technologies (EE). As a control-systems engineer you will own the algorithms that keep our drones stable, responsive, and mission-capable without satellite guidance. What you will be doing Design, implement, and tune real-time flight-control algorithms (attitude, position, and trajectory loops) targeted at GNSS-denied missions. Develop high-rate state-estimation and sensor-fusion pipelines that blend IMU, barometer, optical flow, VIO, and SLAM data. Port and optimise these pipelines on flight computers (Jetson Orin, Raspberry Pi CM5, i.MX 8M plus) under real-time constraints. Extend and customise PX4 or write bare-metal control stacks where needed. Create Software-in-the-Loop (SITL) and Hardware-in-the-Loop (HITL) test environments; iterate rapidly between simulations and field flights. Instrument test vehicles, run flight campaigns, and mine logs to improve robustness in wind, vibration, and electromagnetic interference. We are looking for Required skills: Proficiency in C++14 and C99 (or newer). Proficiency in Linux environments. Hands-on experience with Linux SBCs such as Raspberry Pi, BeagleBone, or similar. Nice to have: Previous experience with embedded systems, especially STM32 microcontrollers. Hands-on experience with PX4, ArduPilot, or custom flight-control firmware. Practical knowledge of RTK-GPS, UWB, or vision-based localization frameworks. Additional skills that are advantageous Control theory — PID, LQR, observers, pole/zero placement, robustness analysis. Sensor fusion & estimation — Kalman variants, factor graphs, Bayesian filtering. Computer vision — feature tracking, optical flow, homography, depth estimation. Digital comms & electronics — UART, SPI, I²C, CAN-FD, logic-analyzer debugging. What we offer Monthly gross salary €3,500-6,000 based on experience and impact Stock options A mission-driven team that values ownership, curiosity, and a hands-on approach to solving defense challenges Early technical influence in a growing defense tech startup A focus on outcomes Join Lendurai to be part of the forefront of defence technology innovation. Department Engineering Role Software Engineer, Control Systems Locations Tallinn, Estonia Remote status Hybrid Monthly salary €3,500 - €6,000 Employment type Full-time About Lendurai At Lendurai, we enable UAV's to overcome electronic warfare (EW) measures and complete their missions, using computer vision and machine learning. We provide integrated, turnkey drone solutions and also partner with external UAV manufacturers to integrate our terminal guidance solutions into their platforms, delivering cost-effective and customizable capabilities to defence and public sector customers. Founded in 2024