Staff Software Engineer — Runtimes Performance

Arm; Cambridge; On-site; GBP 97,300 - 131,700; Full time

Job summary

Arm is seeking an experienced performance engineer to advance compilers and managed runtimes on Arm. You will optimize language runtimes for Java, JavaScript, Python, Rust and more, profiling to remove bottlenecks and collaborating with hardware teams.

This role offers the chance to contribute to open‑source projects, work with upstream communities, and influence architecture features while delivering high‑impact performance improvements.

Qualifications

• Experience with managed runtimes and compilers.
• Strong programming skills in C/C++.
• Familiar with performance analysis at a low level.
• Interest in CPU pipelines and cache hierarchies.
• Solid software development practices.

Responsibilities

• Identify and implement changes to compilers and runtimes to boost performance.
• Profile workloads to find bottlenecks and optimize features.
• Collaborate across Arm to improve architecture and CPU support.
• Develop runtime or compiler features and tune existing ones.
• Contribute to open‑source projects and engage with the community.
• Help build automated functionality and performance tests.

Skills

Managed runtimes

Compilers

C/C++ programming

Performance analysis

Computer architecture

Tools

Linux profiling tools

CI/build systems

Job description

Overview

We are looking for an experienced performance engineer who is passionate about developing compilers and managed runtimes and loves open‑source software. In this role you will be working on improving the performance of managed language workloads on Arm architecture by improving the language runtime/compiler as well as identifying bottlenecks in the hardware and working with hardware designers to improve these. The languages covered include Java, JavaScript, Python, Rust and more.

Responsibilities

• Identify and implement changes to compilers and managed runtimes to improve the performance of selected workloads and better support Arm architectural features and CPU designs.
• Identify bottlenecks in managed language workloads/benchmarks using profiling tools.
• Collaborate with colleagues across Arm to improve the support for the Arm Architecture and CPUs.
• Implement new runtime or compile features and fine‑tune existing ones (e.g., garbage collectors, interpreters, optimisation passes, intrinsics).
• Contribute to open‑source software projects and engage with open‑source community.
• Help develop the project automated functionality and performance testing frameworks.

Required Skills And Experience

• Experience working on managed runtimes, compilers or similar technologies.
• Strong programming skills in C/C++.
• Familiar with performance analysis tools at an assembly level.
• Knowledge of and interest in improving computer architecture and microarchitecture such as CPU pipelines and cache hierarchies.
• Proficiency in software development and methodologies (coding, testing, debugging, reviewing).

Nice To Have Skills And Experience

• Familiar with Linux performance analysis tools and system‑level performance tuning.
• Proficiency in one or more of the following languages: Java, C#, Rust, Go, JavaScript, Python.
• Familiar with Agile software development methodology such as Scrum or Kanban.
• Familiar with build systems and CI.
• Familiar with open‑source project development and contribution processes.

In Return

You will work directly with upstream communities, contributing to language implementations used by millions of developers worldwide. You will have the opportunity to learn about and influence the latest Arm architecture features and microarchitectural implementations, working closely with highly skilled engineering teams on ground‑breaking technology. You will be empowered to continually identify and roll out improvements to our ways of working.

Equal Opportunities

Arm is an equal opportunity employer, committed to providing an environment of mutual respect where equal opportunities are available to all applicants and colleagues. We are a diverse organization of dedicated and innovative individuals, and don’t discriminate on the basis of race, color, religion, sex, sexual orientation, gender identity, national origin, disability, or status as a protected veteran.

Salary Range

£97,300 - £131,700 per year