Principal Kernel Engineer

Principal Kernel Engineer

A global Tech leader in ICT infrastructure and R&D Giant is hiring a Principal Kernel Engineer to join their specialized team in Cambridge

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In this role, you will drive deep kernel performance and power optimization for flagship mobile platforms. You will own performance across core kernel subsystems — memory management, scheduling, IPC, and synchronization — analysing behaviour on real silicon down to the microarchitectural level and landing production-shippable optimizations that improve responsiveness, throughput, and battery life.

This is a hands-on position for an engineer who is at home in allocator internals, scheduler hot paths, and lock-contention traces, working alongside CPU microarchitects, runtime engineers, and AI-driven optimization tooling.

Key Responsibilities

• Optimize Memory Management Internals: Buddy allocator, slab/SLUB, page reclaim and LRU/MGLRU, memory compaction/defragmentation, transparent huge pages, page-fault/TLB-shootdown paths, and copy-on-write behaviour.
• Drive Scheduler Performance: Run-queue and load-balancing behaviour, energy-aware scheduling, wakeup latency, task placement on heterogeneous (big.LITTLE/DynamIQ) topologies, and cpufreq/cpuidle governor interaction.
• Optimize Synchronization Primitives: Futex fast/slow paths, mutexes/rwsems, spinlocks/qspinlocks, RCU, seqlocks, per-CPU data, and memory ordering/barriers on ARM64.
• Analyse IPC & Syscall Paths: Context-switch cost, binder-style IPC, shared memory, vDSO, and interrupt/softirq handling.
• Identify Bottlenecks: Evaluate flagship mobile workloads (gaming, day-of-use, camera, AI inference) using PMU counters, ftrace/perf, eBPF, lockdep/lockstat, and power measurement with mA/mAh attribution.
• Deliver Production-Quality Patches: Bring patches from hypothesis through benchmarking to ship, ensuring measured latency and energy impact.
• HW-SW Co-Design: Collaborate with CPU microarchitects to exploit microarchitectural features in the kernel and shape future hardware through kernel-driven requirements.
• AI Pipelines: Contribute to AI-assisted kernel optimization pipelines

Profile Required

Technical Essentials

• 10+ years of OS kernel development in C (Linux or comparable), with patches shipped to production systems at scale.
• Expert-level MM internals: Physical/virtual memory management, buddy and slab allocation, reclaim, compaction, page tables, and TLB management.
• Deep scheduler knowledge: CFS/EEVDF internals, load balancing, preemption, real-time classes, and energy-aware scheduling.
• Mastery of kernel synchronization: Locking primitives, RCU, lock-free techniques, the ARM64 memory model, and barrier semantics.
• Kernel performance analysis: PMU counters, ftrace/perf, eBPF, lock contention, and latency analysis.
• Strong ARM64 architecture grounding: Exception levels, cache hierarchy and maintenance, TLBs, and memory ordering.

Preferred Extras

• Mobile power engineering: DVFS governors, cpuidle, and per-workload energy attribution.
• Upstream Linux kernel contributions (mm, sched, locking, or related subsystems).
• Familiarity with mobile platforms: HarmonyOS or Android common kernel.
• CPU Microarchitecture: Exposure to cycle-accurate modelling (gem5).
• Modern Tooling: Experience with LLM/agentic tooling applied to systems software.

Interested? Apply directly through LinkedIn, or send your CV to george@eu-recruit.com

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