Sr. Staff Performance Tuning Engineer (CPU PMU & Virtualization)

Job description

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