Nio.com

## Sr. Staff Performance Tuning Engineer (CPU PMU & Virtualization)Applyremote type: Onsitelocations: San Jose-UStime type: Full timeposted on: Posted 8 Days Agojob requisition id: R-000151****JOB DESCRIPTION******About NIO**NIO is a pioneer and a leading company in the premium smart electric vehicle market. Founded in November 2014, NIO’s mission is to shape a joyful lifestyle. NIO aims to build a community starting with smart electric vehicles to share joy and grow together with users.NIO designs, develops, jointly manufactures and sells premium smart electric vehicles, driving innovations in next-generation technologies in autonomous driving, digital technologies, electric powertrains and batteries. NIO differentiates itself through its continuous technological breakthroughs and innovations, such as its industry-leading battery swapping technologies, Battery as a Service, or BaaS, as well as its proprietary autonomous driving technologies and Autonomous Driving as a Service, or ADaaS.NIO’s product portfolio consists of the ES8, a six-seater smart electric flagship SUV, the ES7 (or the EL7), a mid-large five-seater smart electric SUV, the ES6, a five-seater all-round smart electric SUV, the EC7, a five-seater smart electric flagship coupe SUV, the EC6, a five-seater smart electric coupe SUV, the ET7, a smart electric flagship sedan, and the ET5, a mid-size smart electric sedan.**Responsibilities****Performance Analysis and Optimization*** Identify and analyze performance bottlenecks across CPU, memory hierarchy, cache, interconnect, and interrupt subsystems.* Leverage hardware PMU counters to measure and interpret cycles, instructions, cache misses, branch mispredictions, TLB misses, and stall cycles.* Compute and analyze performance metrics such as IPC, CPI, MPKI, memory bandwidth utilization, and stall breakdowns.* Optimize system software, applications, and drivers for throughput, latency, and performance determinism.**Virtualization Performance Tuning*** Profile and reduce hypervisor overhead, including VM exits, interrupt injection, and stage-2 MMU translation costs.* Optimize vCPU placement strategies, huge page usage, and IRQ affinity for performance-sensitive workloads.* Analyze and tune virtio and IOMMU performance paths.* Investigate cross-core and cross-cluster latency issues, including IPI overhead and interrupt routing on ARM-based systems.**CPU PMU and Microarchitectural Analysis*** Configure and interpret ARM PMUv3 and related vendor-specific performance monitoring extensions.* Apply Top-Down Microarchitecture Analysis (TMA) to identify frontend/backend bottlenecks.* Correlate PMU-derived metrics with kernel traces, source code paths, and system behavior.* Design and implement custom event sets tailored to workload-specific performance characterization.**Required Qualifications*** Bachelor’s, Master’s, or Ph.D. in Computer Science, Electrical Engineering, or a related field.* 8+ years of experience in system performance engineering or related roles.* Strong understanding of computer architecture, including: + CPU pipelines, execution engines, and memory hierarchy + Interrupt architectures (e.g., GICv3/GICv4, APIC concepts) + MMU, virtual memory, and page table structures* Deep expertise with Linux performance tooling: + perf + eBPF / BCC / bpftrace + ftrace / trace-cmd* Proficiency in C/C++, Python, and shell scripting for performance tooling and automation.**Preferred Qualifications*** Hands-on experience with ARM PMUv3 on Cortex-A55/A76/A78 or Neoverse platforms.* Experience with one or more virtualization stacks: + KVM/QEMU + Xen + seL4 or other RTOS/hypervisor environments**Compensation:**The US base salary range for this full-time position is $192,100.00 - $249,600.00.* Within the range, individual pay is determined by work location and additional factors, including job-related skills, experience, and relevant education or training.* Please note that the compensation details listed in US role postings reflect the base salary only. It does not include discretionary bonus, equity, or benefits.**Benefits:**Along with competitive pay, as a full-time NIO employee, you are eligible for the following benefits on the first day you join NIO:* Anthem Blue Cross, HSA, and Kaiser HMO medical plans with $0 for Employee Only Coverage.* Dental (including orthodontic coverage) and vision plan. Both provide options with a $0 paycheck contribution covering you and your eligible dependents.* Company Paid HSA (Health Savings Account) Contribution when enrolled in the High Deductible Anthem Blue Cross medical plan* Healthcare and Dependent Care Flexible Spending Accounts (FSA)* 401(k) with Brokerage Link option* Company paid Basic Life, AD&D, short-term and long-term disability insurance* Employee Assistance Program* Sick and Vacation time* 13 Paid Holidays a year* Paid Parental Leave for first 8 weeks at full pay (eligible after 90 days of employment with NIO)* Paid Disability Leave for first 6 weeks at full pay (eligible after 90 days of employment with NIO)* Voluntary benefits including: Voluntary Life and AD&D options for you, your spouse/domestic partner and dependent child(ren), pet insurance* Commuter benefits* Mobile Cell Phone Credit* Free lunch and snacks* Onsite gym* Employee discounts and perks program #J-18808-Ljbffr