
Proton · London
Join Proton and build a better internet where privacy is the default Proton was founded in 2014 by scientists from CERN on a simple truth: privacy is a fundame...
Join Proton and build a better internet where privacy is the default
Proton was founded in 2014 by scientists from CERN on a simple truth: privacy is a fundamental human right. Since then, we’ve
built the world’s largest encrypted email service (Proton Mail) and expanded into Proton VPN, Proton Drive, Proton Pass, and
Proton Calendar—tools used by millions globally to protect their freedom, fight censorship, and keep their data safe. In some
situations, Proton has literally helped save lives!
We are profitable, independent (no VC control), and selectively hire from the top ~1% of applicants. Our 500+ team members across
50+ countries come from leading organizations and elite academic backgrounds. We move fast, keep hierarchy light, and prioritize
impact over optics. If you want to do meaningful work with exceptionally high-caliber people, this is it. Join us and do work you
can truly be proud of. Check our open-source projects here!
The Proton Drive Desktop Team
Proton Drive is our secure, private cloud storage and collaborative editing suite, with clients on Windows, Mac, iOS, Android, and
Web. One platform is missing: Linux. You will build it from scratch. This is a greenfield project with high visibility inside
Proton and across the open-source community — our entire client codebase is published under an open-source license, and this will
be the first public example of how to build a native application on top of the Proton Drive SDK. You will work closely with our
Windows and Mac engineers to ensure feature parity, and you will contribute to our platform-agnostic SDK and CLI tooling as the
Linux surface area demands it. If building something that the Linux community has been waiting for, and doing it in the open, is
the kind of work that gets you out of bed — this role is for you.
Tech Stack and Tools
What You'll Do
developers beyond Proton.
cross-client use.
interface (i.e., GUI apps as well as CLI apps).
platforms)
What we offer
investors with conflicting agendas, not governments. The work you do here is real, and the impact is measurable. (read more
about our impact here)
the world’s top academic institutions and organizations, such as MIT, Harvard, Stanford, Caltech, Cambridge, and ETH.
accelerate your career because you'll be thrown into real challenges, with real ownership, from day one.
leave, and wellness support so you can bring your best self to work every day
we're building. When Proton wins, you win.
With offices across Geneva, Zürich, Barcelona, London and more, you'll spend most of your time collaborating face-to-face with
people who genuinely care about what they're building
for you.
clock says you started.
Our commitment to diversity and inclusion
At Proton, we believe diversity drives innovation and strengthens our mission to provide privacy as a default for all. We are
committed to fostering an inclusive environment where all individuals, regardless of race, ethnicity, gender, age, sexual
orientation, physical ability or socio-economic background feel valued and empowered. We strive to create equal opportunities,
promote open dialogue and support continuous learning to ensure every voice is heard and respected.
If you need any extra support or reasonable adjustments during the hiring process, please let your talent partner know.
Candidate privacy notice
When you apply for a position, refer a candidate or are considered for a role at Proton Technologies AG (Proton, we, us or our),
your information is stored in Greenhouse, in accordance with its Service Privacy Policy. This information is used to evaluate your
suitability for the posted position. We also retain this information for consideration for future roles that you may apply for or
that we believe may align with your background and skills.
If we no longer have a legitimate business need to process your information, we will either delete or anonymise it. Should you
have any inquiries about how we use or manage your information or if you wish to access, correct or delete your data, please
contact our privacy team at careers@proton.ch.
Proton does not accept unsolicited CVs from any sources other than directly from candidates. We will not pay a fee for any
placement resulting from an unsolicited offer, even if the candidate is subsequently hired by Proton.
To learn more about our privacy policy, please visit our privacy policy page.
ABOUT GRAPHCORE Graphcore is one of the world’s leading innovators in Artificial Intelligence compute. It is developing hardware, software and systems infrastructure that will unlock the next generation of AI breakthroughs and power the widespread adoption of AI solutions across every industry. As part of the SoftBank Group, Graphcore is a member of an elite family of companies responsible for some of the world’s most transformative technologies. Together, they share a bold vision: to enable Artificial Super Intelligence and ensure its benefits are accessible to everyone. Graphcore’s teams are drawn from diverse backgrounds and bring a broad range of skills and perspectives. A melting pot of AI research specialists, silicon designers, software engineers and systems architects, Graphcore enjoys a culture of continuous learning and constant innovation. JOB SUMMARY Join our dynamic Software Infrastructure team and take a pivotal role in scaling and managing our infrastructure. You will develop essential tools and services that empower our broader software team. Your contributions will enhance the build, test, deployment, and productisation processes of our Machine Learning Software components. Work with our High-Performance Computing (HPC) AI platforms and gain invaluable experience in distributed systems. THE TEAM An exciting opportunity to join a new team within the Software Operations group. The Build Engineering team is a new function within Software Infrastructure, which focuses on the overall process of building and integration of the Machine Learning Software Stack. You will work closely with the QA and development teams to get an understanding of how our ML SW stack is built, helping to ensure good build practices, and proving that the stack works together and is reproducible in secure, sandboxed environments. Responsibilities and Duties * Developing our internal tooling for building, testing and integrating together the ML Software Stack * Developing tools and technical processes for Software Releases * Providing guidance to developers on best build practices and dependency management * Communicating regularly with developers, tech leads, and software architects about aspects of the ML Software Stack * Working closely with QA and the ML Software Stack to resolve any integration issues * Contributing fixes towards the ML Software Stack Essential: * Knowledge of Python/C++ (or similar language) * Understanding of Build Processes and Frameworks * Experience working in Linux environments * Good communication skills Desirable: * Experience with Remote Caching and Execution (e.g. Bazel) * Experience with Build Tools (e.g. CMake) * Experience with Testing Frameworks (e.g. PyTest, GoogleTest) * Experience with Integration Tools (e.g. Buildstream) * Experience working within the Software Development Lifecycle (SDLC) * Experience with building and using containers (e.g. Docker, Podman) * An understanding of Software Architecture patterns BENEFITS In addition to a competitive salary, Graphcore offers flexible working, a generous annual leave policy, private medical insurance and health cash plan, a dental plan, pension (matched up to 5%), life assurance and income protection. We have a generous parental leave policy and an employee assistance programme (which includes health, mental wellbeing, and bereavement support). We offer a range of healthy food and snacks at our central Bristol office and have our own barista bar! We welcome people of different backgrounds and experiences; we’re committed to building an inclusive work environment that makes Graphcore a great home for everyone. We offer an equal opportunity process and understand that there are visible and invisible differences in all of us. We can provide a flexible approach to interview and encourage you to chat to us if you require any reasonable adjustments. Applicants for this position must hold the right to work in the UK. Unfortunately at this time, we are unable to provide visa sponsorship or support for visa applications
ABOUT THE JOB Help prove the ML software stack that future AI systems will depend on. Graphcore is expanding the software systems behind AI compute at datacenter scale. This role focuses on validating a complex machine learning stack before it reaches customers and hardware.You will build the test infrastructure, automation and tooling that engineers trust every day. Your work will help raise reliability, performance and maintainability across frameworks, simulators, emulators and future hardware. You will shape test architecture across large codebases, CI pipelines and representative ML workloads. You will use strong software engineering judgement to turn complex technical goals into scalable validation systems. This is a role for someone who enjoys depth, ownership and useful engineering. You will make quality easier, faster and more visible for teams building at the edge of AI compute. THE TEAM AND CULTURE The ML QA team sits where Graphcore’s software components come together. Engineers work across unit tests, integration tests, full model runs, subgraph validation and benchmarking. Work is organised through focused squads with clear ownership. People are expected to step up, speak openly and improve how the team builds, tests and learns. Decisions are grounded in evidence from code, data and system behaviour. The team works closely with software teams to identify gaps, improve tooling and move priorities forward quickly. WHAT WE’RE LOOKING FOR · Strong software design skills, with experience building maintainable systems across large codebases. · Production Python experience, including testable, reliable code used by other engineers. · Experience with CI/CD, automated testing and Linux based development workflows. · Familiarity with C or C++, with confidence reading and debugging low level code. · Understanding of ML frameworks, workloads or model execution beyond simple API usage. · Ability to mentor engineers, improve practices and take ownership of complex technical problems. BENEFITS · Unlimited annual leave · Up to 5% matched pension · Phantom equity – share in Graphcore’s success · True flexibility in how and where you work · Office spaces designed for collaboration · Free food and an on-site barista · Health cash plan · Income protection · Life assurance · Along with other benefits you can choose from (private medical insurance, dental plan etc) We welcome people from all backgrounds and experiences and are committed to building an inclusive environment where everyone can do their best work. We’re an equal opportunity employer and recognise that everyone brings different strengths and perspectives. If you need any adjustments during the interview process, just let us know - we’re happy to support you. JOIN THE TEAM AT GRAPHCORE Graphcore is one of the world’s leading innovators in Artificial Intelligence compute. It is developing hardware, software and systems infrastructure that will unlock the next generation of AI breakthroughs and power the widespread adoption of AI solutions across every industry. As part of the SoftBank Group, Graphcore is a member of an elite family of companies responsible for some of the world’s most transformative technologies. Together, they share a bold vision: to enable Artificial Super Intelligence and ensure its benefits are accessible to everyone. Graphcore’s teams are drawn from diverse backgrounds and bring a broad range of skills and perspectives. A melting pot of AI research specialists, silicon designers, software engineers and systems architects, Graphcore brings together deep expertise to solve complex problems and deliver meaningful progress in AI compute. If you want to shape how complex ML software is tested, trusted and improved, we’d love to hear from you. Apply now to be part of the journey.
ABOUT GRAPHCORE At Graphcore, we’re building the future of AI compute. We’re a team of semiconductor, software and AI experts, with deep experience in creating the complete AI compute stack - from silicon and software to infrastructure at datacenter scale. As part of the SoftBank Group, backed by significant long-term investment, we are delivering key technology into the fast-growing SoftBank AI ecosystem. To meet the vast and exciting AI opportunity, Graphcore is expanding its teams around the world. We are bringing together the brightest minds to solve the toughest problems, in a place where everyone has the opportunity to make an impact on the company, our products and the future of artificial intelligence JOB SUMMARY Applicants for this role should have strong experience designing, developing, and maintaining high-quality software systems. The role focuses on testing and validating a complex machine learning software stack, with particular emphasis on software architecture, automation, and engineering best practices. The ideal candidate is an experienced software engineer who values code quality, testability, and long-term maintainability, and enjoys building systems that other engineers rely on. This person will be comfortable working across large codebases, contributing to CI/CD infrastructure, and shaping technical direction through thoughtful design and mentoring in a technically demanding environment spanning ML frameworks, infrastructure, and AI accelerator hardware THE TEAM The ML QA team is composed of highly skilled software engineers with a strong focus on automation, software quality, and data-driven validation. The team works closely with industry-standard machine learning frameworks and models, contributing to upstream open-source projects and collaborating across the wider software organization. Operating in a fast-paced environment, the team plays a critical role in ensuring reliability, performance, and maintainability across the ML software stack, helping to deliver robust and high-quality products to customers. RESPONSIBILITIES AND DUTIES * Design, implement, and maintain robust test infrastructure and automation for a complex ML software stack. * Architect and evolve test frameworks and tooling with a focus on scalability, maintainability, and developer experience. * Build and maintain CI/CD pipelines targeting simulators, emulators (e.g. QEMU), and physical hardware. * Create representative ML workloads and gain insights from their execution. (Numerical accuracy, performance analysis and benchmarking). * Work closely with all Software development teams, supporting a culture of quality, security and maintainability. * Review code and designs, setting a high bar for software engineering best practices. * Mentor and support junior engineers, helping raise the overall technical capability of the team. * Evaluate existing test strategies and infrastructure, identifying gaps and driving improvements aligned with team and organizational goals. CANDIDATE PROFILE Essential: * Experience in production-quality software engineering roles. * Strong software design and architecture skills, with experience working on large or complex systems. * Strong proficiency in Python, including experience building and maintaining production codebases. * Solid experience with CI/CD systems and automated testing (preferably GitHub-based workflows). * Experience working in Linux environments. * Familiarity with C or C++, with the ability to read, debug, and reason about low-level code when needed. * Proven ability to mentor junior engineers and influence engineering practices within a team. * Strong problem-solving skills and a proactive, self-directed approach to work. * Bachelor/Master's/PhD or equivalent experience in Computer Science, Maths, Machine Learning, Data Science, or related field. Desirable * Exposure to machine learning frameworks such as PyTorch, JAX, Triton, TensorFlow * Experience with distributed workload management systems such as Kubernetes, VLLM, Keras or MLOps pipelines * Experience working with hardware simulators or emulators (e.g. QEMU). * Experience developing for or working with FPGA-based systems. * Experience with people management or mentoring BENEFITS In addition to a competitive salary, Graphcore offers flexible working, a generous annual leave policy, private medical insurance and health cash plan, a dental plan, pension (matched up to 5%), life assurance and income protection. We have a generous parental leave policy and an employee assistance programme (which includes health, mental wellbeing, and bereavement support). We offer a range of healthy food and snacks at our central Bristol office and have our own barista bar! We welcome people of different backgrounds and experiences; we’re committed to building an inclusive work environment that makes Graphcore a great home for everyone. We offer an equal opportunity process and understand that there are visible and invisible differences in all of us. We can provide a flexible approach to interview and encourage you to chat to us if you require any reasonable adjustments. Applicants for this position must hold the right to work in the UK. Unfortunately at this time, we are unable to provide visa sponsorship or support for visa applications