Senior/Principal Performance Engineer

Role Description

CIQ is seeking a highly experienced Senior or Principal Performance Engineer to own and drive system-level and application-level performance across our product portfolio. This is an AI-first role, both in methodology and focus area, and the right candidate will bring deep expertise in operating system internals, kernel and userspace performance, and the performance demands of modern AI workloads, HPC environments, general-purpose computing, and production service workloads.

In this role, you will be the standard-bearer for performance at CIQ. Our performance-focused solutions must always be the fastest in the industry, and you will be responsible for ensuring that remains true. You will be intimately involved with Fuzzball, CIQ's cloud-native computing platform, learning its architecture end-to-end and integrating workloads - both user-facing and CI/testing pipelines - directly through it.

This role is leveled as Senior or Principal based on qualifications and demonstrated capabilities.

Qualifications

• A deep, principled understanding of operating system internals - Linux kernel scheduler, memory subsystem, I/O stack, and networking.
• Proven experience identifying and resolving performance regressions across kernel and user space in production environments.
• Hands-on expertise with profiling and tracing tools: perf, eBPF/bpftrace, Flamegraphs, VTune, Nsight, strace, ftrace, and similar.
• Strong background in AI/ML workload performance - including inference optimization (TensorRT, ONNX, vLLM, or similar), training efficiency, and GPU/accelerator utilization.
• Experience with HPC workloads: MPI, OpenMP, parallel filesystems, RDMA/InfiniBand, and job schedulers (Slurm, PBS, etc.).
• Familiarity with modern AI-first development workflows and comfort using LLM-based tools to accelerate engineering work.
• Experience building automated performance testing and regression detection pipelines in CI/CD environments.
• Excellent analytical skills - able to form hypotheses, design experiments, and draw actionable conclusions from complex data.
• Strong written and verbal communication skills; able to present findings to both deeply technical audiences and business stakeholders.
• A collaborative, humble, and always-learning mindset - combined with the confidence to champion performance as a first-class engineering concern.

Requirements

• PhD in Computer Science, Computer Engineering, or a related field strongly preferred; equivalent industry experience considered.
• 15+ years of industry experience in systems performance engineering, OS development, or a closely related discipline.
• Demonstrated track record of measurable, published, or production-deployed performance improvements at scale.
• Experience working in or with open-source ecosystems (Linux kernel contributions, upstream community engagement) is a strong plus.
• Background with cloud-native, containerized, and/or HPC computing environments preferred.

Benefits

• Medical, dental, and vision insurance.
• Flexible paid time off.
• Employee stock options.
• Remote work; no travel required for most positions.