Senior Software Engineer - CPython Runtime

Arm Limited; Cambridge; Hybrid; GBP 50,000 - 70,000; Full time

Job summary

A leading technology firm in Cambridge is looking for an experienced engineer to develop compilers and managed runtimes. You'll work on CPython and improve support for the Arm architecture. Ideal candidates should have strong programming skills in Python/C and experience with managed runtimes. This role offers a chance to impact real improvements in a collaborative team environment, targeting performance enhancements specific to Arm.

Qualifications

• Experience working on managed runtimes or compilers.
• Strong programming skills in Python/C.
• Familiar with open-source project development and contribution processes.

Responsibilities

• Identify and implement changes to compilers and managed runtimes.
• Own and be accountable for CPython development.
• Collaborate with colleagues to improve Arm Architecture support.

Skills

Strong programming skills in Python/C

Experience working on managed runtimes or compilers

Familiar with open-source project development

Clear written and verbal communication

Flexibility in software development skills

Job description

We are looking for an experienced engineer who is passionate about developing compilers and managed runtimes and loves open-source software. In this role you will be working on CPython. You'll be part of the bigger CE-SW Runtimes team, whose goal is to improve modern languages support on the Arm architecture, from JavaScript to Rust. You will work closely with the team and colleagues across the organisation and with open-source communities to solve challenges in enabling the future of computing.

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.
• Implement new runtime or compiler features and fine-tune existing ones. (e.g. garbage collectors, interpreters, optimisation passes, intrinsics).
• Own and be accountable for medium/large technical areas of CPython development.
• Contribute to CPython and related projects; engage with its upstream communities.
• Collaborate with colleagues across Arm to improve the support for the Arm Architecture and CPUs.
• Help develops the project automated functionality and performance testing frameworks.

Required Skills and Experience

• Experience working on managed runtimes or compilers.
• Strong programming skills in Python/C.
• Be flexible, with a variety of software development skills and a commitment to extend the breadth and depth of knowledge.
• Familiar with open-source project development and contribution processes.
• Knowledge of a computer architecture, arm64 is preferred.
• Proficiency in software development and methodologies (coding, testing, debugging, reviewing).
• Clear and effective written and verbal communication skills.

'Nice To Have' Skills and Experience

• Proficiency in one or more of the following languages: Java, Rust, Go, JavaScript.
• Familiar with Agile software development methodology such as Scrum or Kanban.
• Familiar with Linux performance analysis tools and system level performance tuning.

In Return

You’ll work directly with the upstream CPython community, contributing to the core of the language used by millions of developers worldwide. You’ll have the chance to implement real improvements in the interpreter, targeting performance and architectural enhancements specific to Arm, such as NEON and SVE.

Your work won’t sit in a fork! It will go upstream and become part of Python itself, running everywhere from cloud platforms to embedded systems. You’ll belong to a skilled, collaborative team, and engage with a global open-source community that values clean design, real impact and long-term thinking.

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Accommodations at Arm

At Arm, we want to build extraordinary teams. If you need an adjustment or an accommodation during the recruitment process, please email [e-mail]. To note, by sending us the requested information, you consent to its use by Arm to arrange for appropriate accommodations. All accommodation or adjustment requests will be treated with confidentiality, and information concerning these requests will only be disclosed as necessary to provide the accommodation. Although this is not an exhaustive list, examples of support include breaks between interviews, having documents read aloud, or office accessibility. Please email us about anything we can do to accommodate you during the recruitment process.

Hybrid Working at Arm

Arm’s approach to hybrid working is designed to create a working environment that supports both high performance and personal wellbeing. We believe in bringing people together face to face to enable us to work at pace, whilst recognizing the value of flexibility. Within that framework, we empower groups/teams to determine their own hybrid working patterns, depending on the work and the team’s needs. Details of what this means for each role will be shared upon application. In some cases, the flexibility we can offer is limited by local legal, regulatory, tax, or other considerations, and where this is the case, we will collaborate with you to find the best solution. Please talk to us to find out more about what this could look like for you.

Equal Opportunities at Arm

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.