AI Runtime / Low-Level Software Engineer

As an AI Runtime / Low-Level Software Engineer, you will own the offload runtime layer that enables inference workloads to run efficiently on our custom RISC-V AI accelerator from an x86 host.

You will join our AI & Compute team, which is building a full-stack GenAI inference platform, from serving to silicon: LLM Serving * AI Compilation * Runtime / Offload * Optimized AI Kernel Libraries

You will develop the Low-Level software stack responsible for device lifecycle management, scheduling and workload dispatch, high-performance host-to-device communication, and the runtime APIs exposed to compiler and serving layers. You will build this stack end-to-end on an open software foundation and collaborate closely with hardware, compiler and AI serving teams to drive the solution from emulation to production silicon.

Your main responsibilities will include:

Leading and contributing to:

• Develop and optimize the runtime responsible for executing offloaded inference workloads, from the host offload API to the accelerator firmware.
• Own the performance-critical path, including scheduling, dispatch, memory movement and data flow between the host and the accelerator.
• Profile, analyze and optimize runtime performance by identifying bottlenecks related to latency, memory transfers and execution efficiency.
• Design and maintain clean runtime APIs exposed to AI compiler and serving layers, enabling efficient workload execution on the accelerator.
• Integrate and validate the real PCIe communication path while maintaining emulation environments as CI-tested development platforms.
• Develop engineering foundations including CI/CD pipelines, automated smoke tests on emulated hardware and strong quality standards.
• Collaborate with AI Inference, hardware and architecture teams to influence technical decisions and improve real-world AI performance.
• Contribute to the continuous improvement and reliability of the complete AI acceleration software stack.

• Strong experience in C and/or C++ systems programming on Linux, within large and complex codebases.
• Strong knowledge of parallel and concurrent programming, including threads, memory movement, profiling and performance optimization.
• Experience with embedded software, firmware or bare-metal development, ideally with technologies such as OpenAMP, remoteproc, rpmsg, virtio and shared-memory communication models.
• Good understanding of Linux internals, including concepts such as mmap, sysfs and the Linux device model, as well as PCIe fundamentals (BARs, DMA).
• Experience with RISC-V (or similar ISA), cross-compilation and low-level debugging across the hardware/software boundary.

Nice to have:

• Experience with the GenAI / LLM inference ecosystem, such as vLLM, or AI compilation technologies such as MLIR/LLVM.
• Experience developing kernel drivers (PCIe, remoteproc) and working with QEMU or hardware emulation environments.
• Experience with CI/CD systems targeting hardware or emulation platforms.
• Experience with high-performance data-plane development, including DMA and zero-copy techniques, * MSc or Engineering degree (BAC+5) in Computer Science, Embedded Systems, Computer Engineering or related field.
• 5+ years of experience in low-level software development, embedded systems, runtime development or systems programming.
• Strong ownership mindset and autonomy with the ability to drive a complex software component end-to-end and make sound technical decisions.
• Strong systems-thinking ability, understanding the complete chain from AI serving and compiler layers down to runtime, firmware and hardware.
• Performance-oriented mindset with intuition for identifying where cycles, memory copies and bottlenecks impact execution.
• Rigorous approach to software quality, automation, reproducibility and reliable engineering practices.
• Strong collaboration and communication skills, with the ability to work closely with multidisciplinary teams.
• Comfortable working in an international, fast-evolving startup environment.

• Competitive salary & performance-based RSU (free shares)
• Hybrid work model
• Additional paid leave (RTT)
• Meal vouchers (Edenred)
• Premium health coverage (Malakoff Humanis)
• Sustainable mobility incentives
• Generous paternity leave
• Monthly team activities (laser game, hiking, sailing, karaoke …) and large-scale company events

Kalray is a European leader in hardware acceleration, with full-stack acceleration expertise: from silicon to complete system. Our MPPA® (Massively Parallel Processor Array) architecture is the foundation of Kalray's processor (30+ patent families, 15+ years of development) and acceleration cards that combine processing power, flexibility, and energy efficiency. Our mission is to deliver open data-efficient hardware accelerators to power next generation of data-intensive, AI-driven systems and infrastructures. We offer off-the-shelf processors, acceleration cards, and specialized processor development. With over 130 employees and presence in France and Romania, Kalray is backed by top-tier investors and publicly listed on Euronext Growth. You'll be part of a pioneering team that is shaping the future of computing with cutting-edge processor architecture, software-defined solutions, and next-generation acceleration platforms.