Senior Software Engineer – AI/HPC Middleware

At Cornelis we’re building the future of AI and HPC networking with an AI-first approach to silicon and software development. We’re seeking engineers who are energized by working on cutting-edge ASIC design and distributed software systems, and who are motivated to push the boundaries on how AI can transform everything from chip architecture to system performance at scale.

Cornelis Networks delivers the world’s highest performance scale-out networking solutions for AI and HPC datacenters. Our differentiated architecture seamlessly integrates hardware, software and system level technologies to maximize the efficiency of GPU, CPU and accelerator-based compute clusters at any scale. Our solutions drive breakthroughs in AI & HPC workloads, empowering our customers to push the boundaries of innovation. Backed by top-tier venture capital and strategic investors, we are committed to innovation, performance and scalability - solving the world’s most demanding computational challenges with our next-generation networking solutions.

We are a fast-growing, forward-thinking team of architects, engineers, and business professionals with a proven track record of building successful products and companies. As a global organization, our team spans multiple U.S. states and six countries, and we continue to expand with exceptional talent in onsite, hybrid, and fully remote roles.

We are seeking an experienced Senior Software Engineer to contribute to the design, development, and upstream enablement of Cornelis Networks' AI/HPC communication middleware. This role focuses on enabling and optimizing HPC middleware (MPI/SHMEM) and AI middleware (collective communication libraries / CCL, e.g., NCCL/RCCL and related stacks) over Cornelis Networks' interconnects. You will help drive performance, correctness, and deployability across real customer workloads by collaborating across the stack (drivers/kernel, switches, systems, and application/framework teams) and by contributing upstream to key open-source projects. 

Key Responsibilities

• AI/HPC Middleware Enablement & Optimization: Implement and help optimize features for HPC middleware (HPI and SHMEM) and AI middleware (CCL stacks ie: NCCL/RCCL and related collective communication libraries)
• Transport & Integration: Assist in integrating middleware capabilities with underlying transports and provider layers (ie: libfabric / OFI, UCX, verbs-like semantics where applicable)
• Upstream & Open-Source Leadership: Prepare and submit upstream contributions across MPI/SHMEM projects, CCL ecosystems, and related components
• Cross-Stack Collaboration & Performance Validation: Collaborate with kernel/driver and switch teams to help deliver end-to-end performance aligned to the Cornelis product roadmap
• Customer & Field Impact: Help analyze performance traces and reproduce customer issues, and assist in translating findings into fixes.

Minimum Qualifications

• 6+ years of experience in systems programming in C/C++ on Linux; Bachelor's degree in Computer Science, Engineering, or related field (or equivalent experience). Master's or Doctorate a plus. 
• Hands-on experience with HPC middleware internals (Open MPI, MPICH, MVAPICH, and/or SHMEM) or optimizing collective communications for AI, including NCCL/RCCL, CUDA/ROCm) and/or other CCL stacks. 
• Demonstrated ability to deliver low-latency/high-throughput communication paths and to diagnose performance issues using profiling/tracing tools.
• Working knowledge of transport/integration layers such as OFI/libfabric, UCX, verbs-style concepts. 
  
• Solid background in RDMA concepts and performance tuning. 
  
• Experience contributing to open-source projects. 

Preferred Qualifications

• Prior experience developing or maintaining libfabric providers. 
  
• Familiarity with Ultra Ethernet (UEC/UET) specifications. 
  
• Experience with RoCEv2, congestion control, and/or Ethernet-based RDMA deployments. 
  
• Experience with cluster-scale benchmarking, profiling, and optimization. 
  
• Background with HPC fabrics, such as Omni-Path. 

Location: 

This role may work remote from Costa Rica via an EOR (Employer of Record).

We offer a competitive compensation package that includes base salary, performance incentives and equity participation.

At Cornelis Networks, your compensation is only one component of your comprehensive total rewards package. Compensation will be determined by factors such as experience, qualifications, skills, and location relative to the hiring range for the position. 

Depending on your geographic location, in addition to your total rewards package, you may also be eligible for additional benefits, paid holidays, and flexible work arrangements.

Cornelis Networks does not accept unsolicited resumes from headhunters, recruitment agencies, or fee-based recruitment services. Cornelis Networks is an equal opportunity employer, and all qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity or expression, pregnancy, age, national origin, disability status, genetic information, protected veteran status, or any other characteristic protected by law.